Exhibit 10.3

TWIST BIOSCIENCE CORPORATION

2018 EMPLOYEE STOCK PURCHASE PLAN

ADOPTED BY THE BOARD OF DIRECTORS: SEPTEMBER 26, 2018

APPROVED BY THE STOCKHOLDERS: [ ], 2018

1. General; Purpose.

(a) The Plan provides a means by which Eligible Employees and/or Eligible Service Providers of either the Company or a Designated Company may be given an opportunity to purchase shares of Common Stock. The Plan permits the Company to grant a series of Purchase Rights to Eligible Employees and/or Eligible Service Providers.

(b) The Company, by means of the Plan, seeks to retain and assist its Related Corporations or Affiliates in retaining the services of such Eligible Employees and Eligible Service Providers, to secure and retain the services of new Eligible Employees and Eligible Service Providers and to provide incentives for such persons to exert maximum efforts for the success of the Company and its Related Corporations and Affiliates.

(c) The Plan includes two components: a 423 Component and a Non-423 Component. The Company intends (but makes no undertaking or representation to maintain) the 423 Component to qualify as an Employee Stock Purchase Plan. The provisions of the 423 Component, accordingly, will be construed in a manner that is consistent with the requirements of Section 423 of the Code, including without limitation, to extend and limit Plan participation in a uniform and non-discriminating basis. In addition, this Plan authorizes grants of Purchase Rights under the Non-423 Component that do not meet the requirements of an Employee Stock Purchase Plan. Except as otherwise provided in the Plan or determined by the Board, the Non-423 Component will operate and be administered in the same manner as the 423 Component. In addition, the Company may make separate Offerings which vary in terms (provided that such terms are not inconsistent with the provisions of the Plan or the requirements of an Employee Stock Purchase Plan, except in each case with respect to a Non-423 Component), and the Company will designate which Designated Company is participating in each separate Offering and if any Eligible Service Providers will be eligible to participate in a separate Offering. Eligible Employees will be able to participate in the 423 Component or Non-423 Component of the Plan. Eligible Service Providers will only be able to participate in the Non-423 Component of the Plan.

2. Administration.

(a) The Board will administer the Plan unless and until the Board delegates administration of the Plan to a Committee or Committees, as provided in Section 2(c).

(b) The Board will have the power, subject to, and within the limitations of, the express provisions of the Plan:

(i) To determine how and when Purchase Rights will be granted and the provisions of each Offering (which need not be identical).

(ii) To designate from time to time which Related Corporations of the Company will be eligible to participate in the Plan as Designated 423 Corporations or as Designated Non-423 Corporations, which Affiliates may be excluded from participation in the Plan, and which Designated Companies will participate in each separate Offering (to the extent that the Company makes separate Offerings).

(iii) To designate from time to time which persons will be Eligible Service Providers and which Eligible Service Providers will participate in each separate Offering (to the extent that the Company makes separate Offerings).

(iv) To construe and interpret the Plan and Purchase Rights, and to establish, amend and revoke rules and regulations for its administration. The Board, in the exercise of this power, may correct any defect, omission or inconsistency in the Plan, in a manner and to the extent it deems necessary or expedient to make the Plan fully effective.

(v) To settle all controversies regarding the Plan and Purchase Rights granted under the Plan.

(vi) To suspend or terminate the Plan at any time as provided in Section 12.

(vii) To amend the Plan at any time as provided in Section 12.

(viii) Generally, to exercise such powers and to perform such acts as it deems necessary or expedient to promote the best interests of the Company, its Related Corporations, and Affiliates and to carry out the intent that the 423 Component be treated as an Employee Stock Purchase Plan.

(ix) To adopt such rules, procedures and sub-plans relating to the operation and administration of the Plan as are necessary or appropriate under applicable local laws, regulations and procedures to permit or facilitate participation in the Plan by Employees or Eligible Service Providers who are foreign nationals or employed or providing services or located or otherwise subject to the laws of a jurisdiction outside the United States. Without limiting the generality of, but consistent with, the foregoing, the Board specifically is authorized to adopt rules, procedures, and sub-plans, which, for purposes of the Non-423 Component, may be beyond the scope of Section 423 of the Code, regarding, without limitation, eligibility to participate in the Plan, handling and making of Contributions, establishment of bank or trust accounts to hold Contributions, payment of interest, conversion of local currency, obligations to pay payroll tax, determination of beneficiary designation requirements, withholding procedures and handling of share issuances, any of which may vary according to applicable requirements.

(c) The Board may delegate some or all of the administration of the Plan to a Committee or Committees. If administration is delegated to a Committee, the Committee will have, in connection with the administration of the Plan, the powers theretofore possessed by the Board that have been delegated to the Committee, including the power to delegate to a subcommittee any of the administrative powers the Committee is authorized to exercise (and references in this Plan to the Board

-2-

will thereafter be to the Committee or subcommittee), subject, however, to such resolutions, not inconsistent with the provisions of the Plan, as may be adopted from time to time by the Board. The Board may retain the authority to concurrently administer the Plan with the Committee and may, at any time, revest in the Board some or all of the powers previously delegated. Whether or not the Board has delegated administration of the Plan to a Committee, the Board will have the final power to determine all questions of policy and expediency that may arise in the administration of the Plan.

(d) All determinations, interpretations and constructions made by the Board in good faith will not be subject to review by any person and will be final, binding and conclusive on all persons.

3. Shares of Common Stock Subject to the Plan.

(a) Subject to the provisions of Section 11(a) relating to Capitalization Adjustments, the maximum number of shares of Common Stock that may be issued under the Plan will not exceed 275,225 shares of Common Stock, plus the number of shares of Common Stock that are automatically added on the first day of each Fiscal Year beginning with the 2019 Fiscal Year and ending on (and including) the first day of the 2029 Fiscal Year, in an amount equal to the lesser of (i) one percent (1%) of the total number of shares of Common Stock outstanding on the last day of the calendar month prior to the date of such automatic increase, and (ii) 249,470 shares of Common Stock. Notwithstanding the foregoing, the Board may act prior to the first day of any fiscal year to provide that there will be no January 1st increase in the share reserve for such fiscal year or that the increase in the share reserve for such fiscal year will be a lesser number of shares of Common Stock than would otherwise occur pursuant to the preceding sentence.

(b) If any Purchase Right granted under the Plan terminates without having been exercised in full, the shares of Common Stock not purchased under such Purchase Right will again become available for issuance under the Plan.

(c) The stock purchasable under the Plan will be shares of authorized but unissued or reacquired Common Stock, including shares repurchased by the Company on the open market.

4. Grant of Purchase Rights; Offering.

(a) The Board may from time to time grant or provide for the grant of Purchase Rights to Eligible Employees and/or Eligible Service Providers under an Offering (consisting of one or more Purchase Periods) on an Offering Date or Offering Dates selected by the Board. Each Offering will be in such form and will contain such terms and conditions as the Board will deem appropriate, and, with respect to the 423 Component, will comply with the requirement of Section 423(b)(5) of the Code that all Employees granted Purchase Rights will have the same rights and privileges. The terms and conditions of an Offering will be incorporated by reference into the Plan and treated as part of the Plan. The provisions of separate Offerings need not be identical, but each Offering will include (through incorporation of the provisions of this Plan by reference in the Offering Document or otherwise) the period during which the Offering will be effective, which period will not exceed 27 months beginning with the Offering Date, and the substance of the provisions contained in Sections 5 through 8, inclusive.

-3-

(b) If a Participant has more than one Purchase Right outstanding under the Plan, unless he or she otherwise indicates in forms delivered to the Company: (i) each form will apply to all of his or her Purchase Rights under the Plan, and (ii) a Purchase Right with a lower exercise price (or an earlier-granted Purchase Right, if different Purchase Rights have identical exercise prices) will be exercised to the fullest possible extent before a Purchase Right with a higher exercise price (or a later-granted Purchase Right if different Purchase Rights have identical exercise prices) will be exercised.

(c) The Board will have the discretion to structure an Offering so that if the Fair Market Value of a share of Common Stock on the first Trading Day of a new Purchase Period within that Offering is less than or equal to the Fair Market Value of a share of Common Stock on the Offering Date for that Offering, then (i) that Offering will terminate immediately as of that first Trading Day, and (ii) the Participants in such terminated Offering will be automatically enrolled in a new Offering beginning on the first Trading Day of such new Purchase Period.

5. Eligibility.

(a) Purchase Rights may be granted only to Employees of the Company or, as the Board may designate in accordance with Section 2(b), to Employees of a Related Corporation or an Affiliate or, solely with respect to the Non-423 Component, Eligible Service Providers.

(b) An Employee will not be eligible to be granted Purchase Rights unless, on the Offering Date, the Employee has been employed by the Company, a Related Corporation, or an Affiliate, as the case may be, for such continuous period preceding such Offering Date as the Board may require, but in no event will the required period of continuous employment be equal to or greater than two years. In addition, the Board may provide that no Employee will be eligible to be granted Purchase Rights under the Plan unless, on the Offering Date, such Employee’s customary employment with the Company, the Related Corporation, or the Affiliate, as applicable, is more than 20 hours per week and more than five months per calendar year or such other criteria as the Board may determine consistent with Section 423 of the Code.

(c) No Employee will be eligible for the grant of any Purchase Rights if, immediately after any such Purchase Rights are granted, such Employee owns stock possessing five percent or more of the total combined voting power or value of all classes of stock of the Company or of any Related Corporation. For purposes of this Section 5(c), the rules of Section 424(d) of the Code will apply in determining the stock ownership of any Employee, and stock which such Employee may purchase under all outstanding Purchase Rights and options will be treated as stock owned by such Employee.

(d) As specified by Section 423(b)(8) of the Code, an Eligible Employee may be granted Purchase Rights only if such Purchase Rights, together with any other rights granted under all Employee Stock Purchase Plans of the Company and any Related Corporations or Affiliates, do not permit such Eligible Employee’s rights to purchase stock of the Company or any Related Corporation or Affiliates to accrue at a rate which, when aggregated, exceeds U.S. $25,000 of Fair Market Value of such stock (determined at the time such rights are granted, and which, with respect to the Plan, will be determined as of their respective Offering Dates) for each calendar year in which such rights are outstanding at any time.

-4-

(e) Officers of the Company and any Designated Company, if they are otherwise Eligible Employees, will be eligible to participate in Offerings under the Plan. Notwithstanding the foregoing, the Board may provide in an Offering that Employees who are highly compensated Employees within the meaning of Section 423(b)(4)(D) of the Code will not be eligible to participate.

(f) An Eligible Service Provider will not be eligible to be granted Purchase Rights unless the Eligible Service Provider is providing bonafide services to the Company or a Designated Company on the applicable Offering Date. Eligible Service Providers may also be subject to whatever additional eligibility criteria as the Board may determine even if such criteria is not consistent with Section 423 of the Code.

6. Purchase Rights; Purchase Price.

(a) On each Offering Date, each Eligible Employee or Eligible Service Provider, pursuant to an Offering made under the Plan, will be granted a Purchase Right to purchase up to that number of shares of Common Stock (rounded down to the nearest whole share) purchasable either with a percentage or with a maximum dollar amount, as designated by the Board; provided however, that in the case of Eligible Employees, such percentage or maximum dollar amount will in either case not exceed 15% of such Employee’s earnings (as defined by the Board in each Offering) during the period that begins on the Offering Date (or such later date as the Board determines for a particular Offering) and ends on the date stated in the Offering, which date will be no later than the end of the Offering, unless otherwise provided for in an Offering.

(b) The Board will establish one or more Purchase Dates during an Offering on which Purchase Rights granted for that Offering will be exercised and shares of Common Stock will be purchased in accordance with such Offering.

(c) In connection with each Offering made under the Plan, the Board may specify (i) a maximum number of shares of Common Stock that may be purchased by any Participant on any Purchase Date during such Offering, (ii) a maximum aggregate number of shares of Common Stock that may be purchased by all Participants pursuant to such Offering, and (iii) a maximum aggregate number of shares of Common Stock that may be purchased by all Participants on any Purchase Date under the Offering. If the aggregate purchase of shares of Common Stock issuable on exercise of Purchase Rights granted under the Offering would exceed any such maximum aggregate number, then, in the absence of any Board action otherwise, a pro rata (based on each Participant’s accumulated Contributions) allocation of the shares of Common Stock (rounded down to the nearest whole share) available will be made in as nearly a uniform manner as will be practicable and equitable.

(d) The purchase price of shares of Common Stock acquired pursuant to Purchase Rights will be not less than the lesser of:

(i) an amount equal to 85% of the Fair Market Value of the shares of Common Stock on the Offering Date; or

(ii) an amount equal to 85% of the Fair Market Value of the shares of Common Stock on the applicable Purchase Date.

-5-

7. Participation; Withdrawal; Termination.

(a) An Eligible Employee may elect to authorize payroll deductions as the means of making Contributions by completing and delivering to the Company, within the time specified in the Offering, an enrollment form provided by the Company or any third party designated by the Company (each, a “Company Designee”). The enrollment form will specify the amount of Contributions not to exceed the maximum amount specified by the Board. Each Participant’s Contributions will be credited to a bookkeeping account for such Participant under the Plan and will be deposited with the general funds of the Company except where applicable laws or regulations require that Contributions be deposited with a Company Designee or otherwise be segregated.

(b) If permitted in the Offering, a Participant may begin Contributions with the first payroll or payment date occurring on or after the Offering Date (or, in the case of a payroll date or payment date that occurs after the end of the prior Offering but before the Offering Date of the next new Offering, Contributions from such payroll or payment will be included in the new Offering) or on such other date as set forth in the Offering. If permitted in the Offering, a Participant may thereafter reduce (including to zero) or increase his or her Contributions. If required under applicable laws or regulations or if specifically provided in the Offering, in addition to or instead of making Contributions by payroll deductions, a Participant may make Contributions through a payment by cash, check, or wire transfer prior to a Purchase Date, in a manner directed by the Company or a Company Designee.

(c) During an Offering, a Participant may cease making Contributions and withdraw from the Offering by delivering to the Company or a Company Designee a withdrawal form provided by the Company. The Company may impose a deadline before a Purchase Date for withdrawing. On such withdrawal, such Participant’s Purchase Right in that Offering will immediately terminate and the Company will distribute as soon as practicable to such Participant all of his or her accumulated but unused Contributions without interest and such Participant’s Purchase Right in that Offering will then terminate. A Participant’s withdrawal from that Offering will have no effect on his or her eligibility to participate in any other Offerings under the Plan, but such Participant will be required to deliver a new enrollment form to participate in subsequent Offerings.

(d) Purchase Rights granted pursuant to any Offering under the Plan will terminate immediately if the Participant either (i) is no longer an Eligible Employee or Eligible Service Provider for any reason or for no reason, or (ii) is otherwise no longer eligible to participate. The Company shall have the exclusive discretion to determine when Participant is no longer actively providing services and the date of the termination of employment or service for purposes of the Plan. As soon as practicable, the Company will distribute to such individual all of his or her accumulated but unused Contributions without interest.

(e) During a Participant’s lifetime, Purchase Rights will be exercisable only by such Participant. Purchase Rights are not transferable by a Participant, except by will, by the laws of descent and distribution, or, if permitted by the Company, by a beneficiary designation as described in Section 10.

(f) Unless otherwise specified in the Offering or required by applicable law, the Company will have no obligation to pay interest on Contributions.

-6-

8. Exercise of Purchase Rights.

(a) On each Purchase Date, each Participant’s accumulated Contributions will be applied to the purchase of shares of Common Stock (rounded down to the nearest whole share), up to the maximum number of shares of Common Stock permitted by the Plan and the applicable Offering, at the purchase price specified in the Offering. No fractional shares will be issued unless specifically provided for in the Offering.

(b) Unless otherwise provided in the Offering, if any amount of accumulated Contributions remains in a Participant’s account after the purchase of shares of Common Stock on the final Purchase Date in an Offering, then such remaining amount will not roll over to the next Offering and will instead be distributed in full to such Participant as soon as practicable after the final Purchase Date of such Offering without interest.

(c) No Purchase Rights may be exercised to any extent unless the shares of Common Stock to be issued on such exercise under the Plan are covered by an effective registration statement pursuant to the Securities Act and the Plan is in material compliance with all applicable U.S. federal and state, foreign and other securities, exchange control, and other laws applicable to the Plan. If on a Purchase Date the shares of Common Stock are not so registered or the Plan is not in such compliance, no Purchase Rights will be exercised on such Purchase Date, and the Purchase Date will be delayed until the shares of Common Stock are subject to such an effective registration statement and the Plan is in material compliance, except that the Purchase Date will in no event be more than three (3) months from the Offering Date. If, on the Purchase Date, as delayed to the maximum extent permissible, the shares of Common Stock are not registered and the Plan is not in material compliance with all applicable laws or regulations, as determined by the Company in its sole discretion, no Purchase Rights will be exercised and all accumulated but unused Contributions will be distributed as soon as practicable to the Participants without interest.

9. Covenants of the Company. The Company will seek to obtain from each U.S. federal or state, foreign or other regulatory commission or agency having jurisdiction over the Plan such authority as may be required to grant Purchase Rights and issue and sell shares of Common Stock thereunder unless the Company determines, in its sole discretion, that doing so would cause the Company to incur costs that are unreasonable. If, after commercially reasonable efforts, the Company is unable to obtain the authority that counsel for the Company deems necessary for the grant of Purchase Rights or the lawful issuance and sale of Common Stock under the Plan, and at a commercially reasonable cost, the Company will be relieved from any liability for failure to grant Purchase Rights or to issue and sell Common Stock on exercise of such Purchase Rights.

10. Designation of Beneficiary.

(a) The Company may, but is not obligated to, permit a Participant to submit a form designating a beneficiary who will receive any shares of Common Stock or Contributions from the Participant’s account under the Plan if the Participant dies before such shares or Contributions are delivered to the Participant. The Company may, but is not obligated to, permit the Participant to change such designation of beneficiary. Any such designation or change must be on a form approved by the Company or as approved by the Company for use by a Company Designee.

-7-

(b) If a Participant dies, in the absence of a valid beneficiary designation, the Company will deliver any shares of Common Stock and Contributions to the executor or administrator of the estate of the Participant. If no executor or administrator has been appointed (to the knowledge of the Company), the Company, in its sole discretion, may deliver such shares of Common Stock and Contributions, without interest, to the Participant’s spouse, dependents or relatives, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate.

11. Capitalization Adjustments; Dissolution or Liquidation; Corporate Transactions.

(a) In the event of a Capitalization Adjustment, the Board will appropriately and proportionately adjust: (i) the class(es) and maximum number of securities subject to the Plan pursuant to Section 3(a), (ii) the class(es) and maximum number of securities by which the share reserve is to increase automatically each year pursuant to Section 3(a), (iii) the class(es) and number of securities subject to, and the purchase price applicable to outstanding Offerings and Purchase Rights, and (iv) the class(es) and number of securities that are the subject of the purchase limits under each ongoing Offering. The Board will make these adjustments, and its determination will be final, binding, and conclusive.

(b) In the event of a dissolution or liquidation of the Company, the Board will shorten any Offering then in progress by setting a New Purchase Date prior to the consummation of such proposed dissolution or liquidation. The Board will notify each Participant in writing, prior to the New Purchase Date that the Purchase Date for the Participant’s Purchase Rights has been changed to the New Purchase Date and that such Purchase Rights will be automatically exercised on the New Purchase Date, unless prior to such date the Participant has withdrawn from the Offering as provided in Section 7.

(c) In the event of a Corporate Transaction, then: (i) any surviving corporation or acquiring corporation (or the surviving or acquiring corporation’s parent company) may assume or continue outstanding Purchase Rights or may substitute similar rights (including a right to acquire the same consideration paid to the stockholders in the Corporate Transaction) for outstanding Purchase Rights, or (ii) if any surviving or acquiring corporation (or its parent company) does not assume or continue such Purchase Rights or does not substitute similar rights for such Purchase Rights, then the Participants’ accumulated Contributions will be used to purchase shares of Common Stock (rounded down to the nearest whole share) prior to the Corporate Transaction under the outstanding Purchase Rights (with such actual date to be determined by the Board in its sole discretion), and the Purchase Rights will terminate immediately after such purchase. The Board will notify each Participant in writing, prior to the New Purchase Date that the Purchase Date for the Participant’s Purchase Rights has been changed to the New Purchase Date and that such Purchase Rights will be automatically exercised on the New Purchase Date, unless prior to such date the Participant has withdrawn from the Offering as provided in Section 7.

12. Amendment, Termination or Suspension of the Plan.

(a) The Board may amend the Plan at any time in any respect the Board deems necessary or advisable. However, except as provided in Section 11(a) relating to Capitalization Adjustments, stockholder approval will be required for any amendment of the Plan for which

-8-

stockholder approval is required by applicable laws, regulations or listing requirements, including any amendment that either (i) materially increases the number of shares of Common Stock available for issuance under the Plan, (ii) materially expands the class of individuals eligible to become Participants and receive Purchase Rights, (iii) materially increases the benefits accruing to Participants under the Plan or materially reduces the price at which shares of Common Stock may be purchased under the Plan, (iv) materially extends the term of the Plan, or (v) expands the types of awards available for issuance under the Plan, but in each of (i) through (v) above only to the extent stockholder approval is required by applicable laws, regulations, or listing requirements.

(b) The Board may suspend or terminate the Plan at any time. No Purchase Rights may be granted under the Plan while the Plan is suspended or after it is terminated.

(c) Any benefits, privileges, entitlements, and obligations under any outstanding Purchase Rights granted before an amendment, suspension, or termination of the Plan will not be materially impaired by any such amendment, suspension, or termination except (i) with the consent of the person to whom such Purchase Rights were granted, (ii) as necessary to comply with any laws, listing requirements, or governmental regulations (including, without limitation, the provisions of Section 423 of the Code and the regulations and other interpretive guidance issued thereunder relating to Employee Stock Purchase Plans) including without limitation any such regulations or other guidance that may be issued or amended after the date the Plan is adopted by the Board, or (iii) as necessary to obtain or maintain any special tax, listing, or regulatory treatment. To be clear, the Board may amend outstanding Purchase Rights without a Participant’s consent if such amendment is necessary to ensure that the Purchase Right or the 423 Component complies with the requirements of Section 423 of the Code.

13. Section 409A of the Code; Tax Qualification.

(a) Purchase Rights granted under the 423 Component are intended to be exempt from the application of Section 409A of the Code under U.S. Treasury Regulation Section 1.409A-1(b)(5)(ii). Purchase Rights granted under the Non-423 Component to U.S. taxpayers are intended to be exempt from the application of Section 409A of the Code under the short-term deferral exception and any ambiguities will be construed and interpreted in accordance with such intent. Subject to Section 13(b) below, Purchase Rights granted to U.S. taxpayers under the Non-423 Component will be subject to such terms and conditions that will permit such Purchase Rights to satisfy the requirements of the short-term deferral exception available under Section 409A of the Code, including the requirement that the shares subject to a Purchase Right be delivered within the short-term deferral period. Subject to Section 13(b) below, in the case of a Participant who would otherwise be subject to Section 409A of the Code, to the extent the Board determines that a Purchase Right or the exercise, payment, settlement, or deferral thereof is subject to Section 409A of the Code, the Purchase Right will be granted, exercised, paid, settled, or deferred in a manner that will comply with Section 409A of the Code, including U.S. Department of Treasury regulations and other interpretive guidance issued thereunder, including, without limitation, any such regulations or other guidance that may be issued after the adoption of the Plan. Notwithstanding the foregoing, the Company will have no liability to a Participant or any other party if the Purchase Right that is intended to be exempt from or compliant with Section 409A of the Code is not so exempt or compliant or for any action taken by the Board with respect thereto.

-9-

(b) Although the Company may endeavor to (i) qualify a Purchase Right for special tax treatment under the laws of the United States or jurisdictions outside of the United States, or (ii) avoid adverse tax treatment (e.g., under Section 409A of the Code), the Company makes no representation to that effect and expressly disavows any covenant to maintain special or to avoid unfavorable tax treatment, notwithstanding anything to the contrary in this Plan, including Section 13(a) above. The Company will be unconstrained in its corporate activities without regard to the potential negative tax impact on Participants under the Plan.

14. Effective Date of Plan. The Plan will become effective on the Effective Date. No Purchase Rights will be exercised unless and until the Plan has been approved by the stockholders of the Company, which approval must be within 12 months before or after the date the Plan is adopted (or if required under Section 12(a) above, materially amended) by the Board.

15. Miscellaneous Provisions.

(a) Proceeds from the sale of shares of Common Stock pursuant to Purchase Rights will constitute general funds of the Company.

(b) A Participant will not be deemed to be the holder of, or to have any of the rights of a holder with respect to, shares of Common Stock subject to Purchase Rights unless and until the Participant’s shares of Common Stock acquired on exercise of Purchase Rights are recorded in the books of the Company (or its transfer agent).

(c) The Plan and Offering do not constitute an employment or service contract. Nothing in the Plan or in the Offering will in any way alter the at-will nature of a Participant’s employment, if applicable, or be deemed to create in any way whatsoever any obligation on the part of any Participant to continue his or her employment or service relationship with the Company, a Related Corporation, or an Affiliate, or on the part of the Company, a Related Corporation, or an Affiliate to continue the employment or service of a Participant.

(d) The provisions of the Plan will be governed by the laws of the State of Delaware without resort to that state’s conflicts of laws rules. For purposes of litigating any dispute that may arise directly or indirectly from the Plan or any Offering, the parties hereby submit and consent to the exclusive jurisdiction of the State of California and agree that any such litigation shall be conducted only in the courts of California or the federal courts of the United States located in California and no other courts.

(e) If any particular provision of the Plan is found to be invalid or otherwise unenforceable, such provision will not affect the other provisions of the Plan, but the Plan will be construed in all respects as if such invalid provision were omitted.

(f) If any provision of the Plan does not comply with applicable law or regulations, such provision will be construed in such a manner as to comply with applicable law or regulations.

-10-

16. Definitions. As used in the Plan, the following definitions will apply to the capitalized terms indicated below:

(a) “423 Component” means the part of the Plan, which excludes the Non-423 Component, pursuant to which Purchase Rights that satisfy the requirements for an Employee Stock Purchase Plan may be granted to Eligible Employees.

(b) “Affiliate” means any entity, other than a Related Corporation, in which the Company has an equity or other ownership interest or that is directly or indirectly controlled by, controls, or is under common control with the Company, in all cases, as determined by the Board, whether now or hereafter existing.

(c) “Board” means the Board of Directors of the Company.

(d) “Capitalization Adjustment” means, with respect to the Common Stock subject to the Plan or subject to any Purchase Right after the date the Plan is adopted by the Board, a stock split, reverse stock split, stock dividend, combination, consolidation, recapitalization (including a recapitalization through a large nonrecurring cash dividend) or reclassification of the Common Stock, subdivision of the Common Stock, a rights offering, a reorganization, merger, spin-off, split-up, repurchase, or exchange of Common Stock or other securities of the Company or other significant corporate transaction, or other change affecting the Common Stock occurs.

(e) “Code” means the U.S. Internal Revenue Code of 1986, as amended, including any applicable regulations and guidance thereunder.

(f) “Committee” means a committee of one or more members of the Board to whom authority has been delegated by the Board in accordance with Section 2(c).

(g) “Common Stock” means the common stock of the Company.

(h) “Company” means Twist Bioscience Corporation, a Delaware corporation.

(i) “Contributions” means the payroll deductions or other payments specifically provided for in the Offering that a Participant contributes to fund the exercise of a Purchase Right. A Participant may make additional payments into his or her account if specifically provided for in the Offering, and then only if the Participant has not already contributed the maximum permitted amount of payroll deductions and other payments during the Offering.

(j) “Corporate Transaction” means the consummation, in a single transaction or in a series of related transactions, of any one or more of the following events:

(i) a transfer of all or substantially all of the Company’s assets;

(ii) a merger, consolidation or other capital reorganization or business combination transaction of the Company with or into another corporation, entity or person; or

(iii) the consummation of a transaction, or series of related transactions, in which any “person” (as such term is used in Sections 13(d) and 14(d) of the Exchange Act) becomes the “beneficial owner” (as defined in Rule 13d-3 of the Exchange Act), directly or indirectly, of more than 50% of the Company’s then outstanding capital stock.

-11-

(k) “Designated 423 Corporation” means any Related Corporation selected by the Board as participating in the 423 Component.

(l) “Designated Company” means any Designated Non-423 Corporation or Designated 423 Corporation, provided, however, that at any given time, a Related Corporation participating in the 423 Component will not be a Related Corporation participating in the Non-423 Component.

(m) “Designated Non-423 Corporation” means any Related Corporation or Affiliate selected by the Board as participating in the Non-423 Component.

(n) “Director” means a member of the Board.

(o) “Effective Date” means the day immediately prior to the Registration Date.

(p) “Eligible Employee” means an Employee who meets the requirements set forth in the document(s) governing the Offering for eligibility to participate in the Offering, provided that such Employee also meets the requirements for eligibility to participate set forth in the Plan. For purposes of the Plan, the employment relationship will be treated as continuing intact while the Employee is on sick leave or other leave of absence approved by the Company or a Related Corporation (including an Affiliate) that directly employs the Employee. Where the period of leave exceeds three (3) months and the Employee’s right to reemployment is not guaranteed either by statute or by contract, the employment relationship will be deemed to have terminated three (3) months and one (1) day following the commencement of such leave.

(q) “Eligible Service Provider” means a natural person other than an Employee or Director who (i) is designated by the Committee to be an “Eligible Service Provider, (ii) provides bonafide services to the Company or a Related Corporation, (iii) is not a U.S. taxpayer and (iv) meets the requirements set forth in the document(s) governing the Offering for eligibility to participate in the Offering, provided that such person also meets the requirements for eligibility to participate set forth in the Plan.

(r) “Employee” means any person, including an Officer or Director, who is treated as an employee in the records of the Company or a Related Corporation (including an Affiliate). However, service solely as a Director, or payment of a fee for such services, will not cause a Director to be considered an “Employee” for purposes of the Plan.

(s) “Employee Stock Purchase Plan” means a plan that grants Purchase Rights intended to be options issued under an “employee stock purchase plan,” as that term is defined in Section 423(b) of the Code.

(t) “Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended and the rules and regulations promulgated thereunder.

(u) “Fair Market Value” means, as of any date, the value of the Common Stock determined as follows:

(i) If the Common Stock is listed on any established stock exchange or a national market system, its Fair Market Value will be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such exchange or system on the date of determination, as reported in such source as the Board deems reliable;

-12-

(ii) If the Common Stock is regularly quoted by a recognized securities dealer but selling prices are not reported, its Fair Market Value will be the mean of the closing bid and asked prices for the Common Stock on the date of determination, as reported in such source as the Board deems reliable;

(iii) In the absence of an established market for the Common Stock, the Fair Market Value will be determined in good faith by the Board in compliance with applicable laws and regulations and in a manner that complies with Sections 409A of the Code; or

(iv) Notwithstanding the foregoing, for any Offering that commences on the Registration Date, the Fair Market Value of the shares of Common Stock on the Offering Date will be the price per share at which shares are first sold to the public in the Company’s initial public offering as specified in the final prospectus for that initial public offering.

(v) “Fiscal Year” means the fiscal year of the Company.

(w) “New Purchase Date” means a new Purchase Date set by shortening any Offering then in progress.

(x) “Non-423 Component” means the part of the Plan, which excludes the 423 Component, pursuant to which Purchase Rights that are not intended to satisfy the requirements for an Employee Stock Purchase Plan may be granted to Eligible Employees and Eligible Service Providers.

(y) “Offering” means the grant to Eligible Employees or Eligible Service Providers of Purchase Rights, with the exercise of those Purchase Rights automatically occurring at the end of one or more Purchase Periods. The terms and conditions of an Offering will generally be set forth in the “Offering Document” approved by the Board for that Offering.

(z) “Offering Date” means a date selected by the Board for an Offering to commence.

(aa) “Officer” means a person who is an officer of the Company or a Related Corporation or Affiliate within the meaning of Section 16 of the Exchange Act.

(bb) “Participant” means an Eligible Employee or Eligible Service Provider who holds an outstanding Purchase Right.

(cc) “Plan” means this Twist Bioscience Corporation 2018 Employee Stock Purchase Plan, including both the 423 Component and the Non-423 Component, as amended from time to time.

(dd) “Purchase Date” means one or more dates during an Offering selected by the Board on which Purchase Rights will be exercised and on which purchases of shares of Common Stock will be carried out in accordance with such Offering.

-13-

(ee) “Purchase Period” means a period of time specified within an Offering, generally beginning on the Offering Date or on the first Trading Day following a Purchase Date, and ending on a Purchase Date. An Offering may consist of one or more Purchase Periods.

(ff) “Purchase Right” means an option to purchase shares of Common Stock granted pursuant to the Plan.

(gg) “Registration Date” means the effective date of the first registration statement that is filed by the Company and declared effective pursuant to Section 12(g) of the Exchange Act, with respect to any class of the Company’s securities.

(hh) “Related Corporation” means any “parent corporation” or “subsidiary corporation” of the Company whether now or subsequently established, as those terms are defined in Sections 424(e) and (f), respectively, of the Code.

(ii) “Securities Act” means the U.S. Securities Act of 1933, as amended.

(jj) “Trading Day” means any day on which the exchange or market on which shares of Common Stock are listed is open for trading.

o O o

-14-