Note 13. Income Taxes

The components of loss before provision (benefit) for income taxes were as follows (in thousands):

	Year Ended January 31,
	2016			2015			2014
United States	$	(155,794	)	$	(132,084	)	$	(148,032	)
Foreign		(46,464	)		(36,712	)		(22,956	)
Total	$	(202,258	)	$	(168,796	)	$	(170,988	)

The components of the provision (benefit) for income taxes were as follows (in thousands):

	Year Ended January 31,
	2016		2015			2014
Current:
Federal	$	29	$	25		$	17
State		146		135			53
Foreign		298		670			89
Total	$	473	$	830		$	159
Deferred:
Federal	$	61	$	(1,009	)	$	(2,360	)
State		—		(109	)		(230	)
Foreign		156		(281	)		—
Total	$	217	$	(1,399	)	$	(2,590	)
Provision (benefit) for income taxes	$	690	$	(569	)	$	(2,431	)

The items accounting for the difference between income taxes computed at the federal statutory income tax rate of 34% and the provision for income taxes consisted of the following (in thousands):

	Year Ended January 31,
	2016			2015			2014
Tax benefit at federal statutory rate	$	(68,767	)	$	(57,391	)	$	(58,136	)
State taxes, net of federal benefit		(8,799	)		(5,322	)		(5,071	)
Foreign rate difference		6,744			4,043			3,270
Nondeductible expenses		429			451			3,408
Research and development credit		(3,533	)		(2,396	)		(1,934	)
Stock-based compensation		6,214			4,703			2,644
Change in reserve for unrecognized tax benefits		3,562			2,421			3,937
Other		61			709			(421	)
Change in valuation allowance		64,779			52,213			49,872
Provision for income taxes	$	690		$	(569	)	$	(2,431	)

The significant components of our deferred tax assets and liabilities were as follows (in thousands):

	January 31,
	2016			2015
Deferred tax assets:
Net operating loss carryforward	$	184,301		$	142,935
Accruals and reserves		26,412			11,917
Stock-based compensation		11,627			7,478
Depreciation and amortization		6,217			3,329
Tax credit carryover		4,002			4,005
Total deferred tax assets		232,559			169,664
Valuation allowance		(232,211	)		(167,436	)
Total deferred tax assets, net of valuation allowance		348			2,228
Deferred tax liabilities:
Acquired intangible assets		(223	)		(1,947	)
Other		(61	)		—
Total deferred tax liabilities		(284	)		(1,947	)
Net deferred tax assets	$	64		$	281

In assessing the realizability of deferred tax assets, we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. As a result, we have established a full valuation allowance against our U.S. and United Kingdom deferred tax assets to the extent they are not offset by liabilities from uncertain tax positions based on our history of losses. The valuation allowance increased by $64.8 million, $52.2 million and $43.1 million, respectively, during the years ended January 31, 2016, 2015 and 2014. During the years ended January 31, 2016, 2015 and 2014, we released $0, $1.1 million and $2.6 million of our valuation allowance as a result of acquisitions. With these acquisitions, deferred tax liabilities were established for the book-tax basis difference related to acquired intangible assets. The net deferred tax liabilities provided an additional source of income to support the realizability of pre-existing deferred tax assets.

We have not provided for U.S. federal and state income taxes on our foreign subsidiary’s undistributed earnings as of January 31, 2016. The net amount of deferred tax liability is considered insignificant.

As of January 31, 2016, we had federal, state and foreign net operating loss carryforwards of $423.7 million, $392.3 million and $125.6 million, respectively, available to offset future taxable income. The federal net operating loss carryforwards will expire at various dates beginning in 2025, if not utilized. The state net operating loss carryforwards will expire at various dates beginning in 2016 if not utilized. The foreign net operating loss carryforwards do not expire. In addition, as of January 31, 2016, we had federal and state research and development tax credit carryforwards of $10.7 million and $11.5 million, respectively. The federal research and development tax credit carryforwards will expire beginning in 2025 if not utilized. The state research and development tax credit carryforwards do not expire.

Included in the net operating loss and research and development tax credit carryforwards are approximately $18.3 million of excess tax benefits from employee stock option exercises, for which the Company has not recorded a deferred tax asset. When such excess tax benefits are ultimately realized, the tax effect of $18.3 million will be recorded to additional paid in capital.

Utilization of the net operating loss carryforwards and credits may be subject to substantial annual limitation due to the ownership change limitations provided by Section 382 of the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of net operating losses and credits before utilization.

We evaluate tax positions for recognition using a more-likely-than-not recognition threshold, and those tax positions eligible for recognition are measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon the effective settlement with a taxing authority that has full knowledge of all relevant information.

A reconciliation of the gross unrecognized tax benefits is as follows (in thousands):

	Year Ended January 31,
	2016		2015			2014
Unrecognized tax benefits—beginning of period	$	13,607	$	8,147		$	2,515
Additions for tax positions related to prior year		238		43			547
Reductions for tax positions related to prior year		—		(19	)		—
Additions for tax positions related to current year		6,811		5,436			5,085
Unrecognized tax benefits—end of period	$	20,656	$	13,607		$	8,147

The gross unrecognized tax benefits, if recognized, would not materially affect the effective tax rate as of January 31, 2016, 2015 and 2014. We do not expect our gross unrecognized tax benefits to change significantly over the next 12 months.

Our policy is to classify interest and penalties associated with uncertain tax positions, if any, as a component of our income tax provision. Interest and penalties were not significant during the years ended January 31, 2016, 2015 and 2014.

We file tax returns in the United States for federal, California, and other states. All tax years remain open to examination for both federal and state purposes as a result of our net operating loss and credit carryforwards. We file foreign tax returns in the United Kingdom starting with the year ended January 31, 2013, in France, Germany and Japan starting with the year ended January 31, 2014 and in Canada starting with the year ended January 31, 2015. These tax years remain open to examination.