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Receivables | 12 Months Ended
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Dec. 31, 2020
Accounts Receivable [Line Items] |
Receivables | RECEIVABLES(a) Accounts Receivable - Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Customer | $101 |  |  | $92 |  |  | $— |  |  | $— |  |  | $92 |  |  | $84 |
Unbilled utility revenues | 82 |  |  | 82 |  |  | — |  |  | — |  |  | 82 |  |  | 82 |
Deferred proceeds | 188 |  |  | 188 |  |  | 188 |  |  | 188 |  |  | — |  |  | — |
Other | 59 |  |  | 47 |  |  | 23 |  |  | 16 |  |  | 35 |  |  | 31 |
Allowance for expected credit losses | (18) |  |  | (7) |  |  | (1) |  |  | (1) |  |  | (17) |  |  | (6) |
| $412 |  |  | $402 |  |  | $210 |  |  | $203 |  |  | $192 |  |  | $191 |
(b) Sales of Accounts Receivable - IPL maintains a Receivables Agreement whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. The purchase commitment from the third party to which it sells its receivables expires in March 2021. IPL currently expects to amend and extend the purchase commitment. IPL pays a monthly fee to the third party that varies based on interest rates, limits on cash proceeds and cash amounts received from the third party. Deferred proceeds represent IPL’s interest in the receivables sold to the third party. At IPL’s request, deferred proceeds are paid to IPL from collections of receivables, after paying any required expenses incurred by the third party and the collection agent. Corporate Services acts as collection agent for the third party and receives a fee for collection services. The Receivables Agreement can be terminated by the third party if arrears or write-offs exceed certain levels. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. IPL believes that the allowance for expected credit losses related to its sales of receivables is a reasonable approximation of credit risk of the customers that generated the receivables. Refer to Note 16 for discussion of the fair value of deferred proceeds. Under the Receivables Agreement, IPL has the right to receive cash proceeds, up to a certain limit, from the third party in exchange for the receivables sold. The limit on cash proceeds fluctuates between $90 million and $110 million. Cash proceeds are used by IPL to meet short-term financing needs, and cannot exceed the current limit or amount of receivables available for sale, whichever is less. As of December 31, 2020, IPL had $109 million of available capacity under its sales of accounts receivable program. IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):
| Maximum |  | Average
| 2020 |  | 2019 |  | 2018 |  | 2020 |  | 2019 |  | 2018
Outstanding aggregate cash proceeds | $96 |  | $108 |  | $116 |  | $9 |  | $36 |  | $53
As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2020 |  | 2019
Customer accounts receivable | $114 |  | $125
Unbilled utility revenues | 92 |  | 95
Other receivables | — |  | 1
Receivables sold to third party | 206 |  | 221
Less: cash proceeds | 1 |  | 27
Deferred proceeds | 205 |  | 194
Less: allowance for expected credit losses | 17 |  | 6
Fair value of deferred proceeds | $188 |  | $188
Outstanding receivables past due | $27 |  | $26
Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2020 |  | 2019 |  | 2018
Collections | $2,025 |  | $2,193 |  | $2,077
Write-offs, net of recoveries | 7 |  | 19 |  | 21
IPL [Member] |
Accounts Receivable [Line Items] |
Receivables | RECEIVABLES(a) Accounts Receivable - Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Customer | $101 |  |  | $92 |  |  | $— |  |  | $— |  |  | $92 |  |  | $84 |
Unbilled utility revenues | 82 |  |  | 82 |  |  | — |  |  | — |  |  | 82 |  |  | 82 |
Deferred proceeds | 188 |  |  | 188 |  |  | 188 |  |  | 188 |  |  | — |  |  | — |
Other | 59 |  |  | 47 |  |  | 23 |  |  | 16 |  |  | 35 |  |  | 31 |
Allowance for expected credit losses | (18) |  |  | (7) |  |  | (1) |  |  | (1) |  |  | (17) |  |  | (6) |
| $412 |  |  | $402 |  |  | $210 |  |  | $203 |  |  | $192 |  |  | $191 |
(b) Sales of Accounts Receivable - IPL maintains a Receivables Agreement whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. The purchase commitment from the third party to which it sells its receivables expires in March 2021. IPL currently expects to amend and extend the purchase commitment. IPL pays a monthly fee to the third party that varies based on interest rates, limits on cash proceeds and cash amounts received from the third party. Deferred proceeds represent IPL’s interest in the receivables sold to the third party. At IPL’s request, deferred proceeds are paid to IPL from collections of receivables, after paying any required expenses incurred by the third party and the collection agent. Corporate Services acts as collection agent for the third party and receives a fee for collection services. The Receivables Agreement can be terminated by the third party if arrears or write-offs exceed certain levels. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. IPL believes that the allowance for expected credit losses related to its sales of receivables is a reasonable approximation of credit risk of the customers that generated the receivables. Refer to Note 16 for discussion of the fair value of deferred proceeds. Under the Receivables Agreement, IPL has the right to receive cash proceeds, up to a certain limit, from the third party in exchange for the receivables sold. The limit on cash proceeds fluctuates between $90 million and $110 million. Cash proceeds are used by IPL to meet short-term financing needs, and cannot exceed the current limit or amount of receivables available for sale, whichever is less. As of December 31, 2020, IPL had $109 million of available capacity under its sales of accounts receivable program. IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):
| Maximum |  | Average
| 2020 |  | 2019 |  | 2018 |  | 2020 |  | 2019 |  | 2018
Outstanding aggregate cash proceeds | $96 |  | $108 |  | $116 |  | $9 |  | $36 |  | $53
As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2020 |  | 2019
Customer accounts receivable | $114 |  | $125
Unbilled utility revenues | 92 |  | 95
Other receivables | — |  | 1
Receivables sold to third party | 206 |  | 221
Less: cash proceeds | 1 |  | 27
Deferred proceeds | 205 |  | 194
Less: allowance for expected credit losses | 17 |  | 6
Fair value of deferred proceeds | $188 |  | $188
Outstanding receivables past due | $27 |  | $26
Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
| 2020 |  | 2019 |  | 2018
Collections | $2,025 |  | $2,193 |  | $2,077
Write-offs, net of recoveries | 7 |  | 19 |  | 21
WPL [Member] |
Accounts Receivable [Line Items] |
Receivables | RECEIVABLES(a) Accounts Receivable - Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Customer | $101 |  |  | $92 |  |  | $— |  |  | $— |  |  | $92 |  |  | $84 |
Unbilled utility revenues | 82 |  |  | 82 |  |  | — |  |  | — |  |  | 82 |  |  | 82 |
Deferred proceeds | 188 |  |  | 188 |  |  | 188 |  |  | 188 |  |  | — |  |  | — |
Other | 59 |  |  | 47 |  |  | 23 |  |  | 16 |  |  | 35 |  |  | 31 |
Allowance for expected credit losses | (18) |  |  | (7) |  |  | (1) |  |  | (1) |  |  | (17) |  |  | (6) |
| $412 |  |  | $402 |  |  | $210 |  |  | $203 |  |  | $192 |  |  | $191 |

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- Definition The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2196772 + Details
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