DFH
Level 3

Determination of tax year of income?

General question:

According to the IRS, what date determines the tax year of income received by check?  Is it the issue date of check, date of receipt, or date of deposit in a bank that determines which tax year such income should be reported?

 

Specific question:

I received a California state tax refund check resulting from an amended filed in 2019 of my 2017 tax year return.  It was dated December 20, 2019 and was received by me prior to December 31, 2019, but I deposited it in my checking account January 8, 2021.  If this income is determined to be taxable (using Worksheets 2a and 2 of Pub. 525), would the IRS consider it to be income in 2019 or in  2020?