pk3
Level 1

Get your taxes done using TurboTax

According to the below (along with the investopedia link from the other answerer), cashback bonuses from Discover would be considered discounts (not income) because they are contingent upon use of the card. They would therefore not have a reporting requirement.
https://www.nerdwallet.com/blog/credit-cards/credit-card-rewards-taxable
https://turbotax.intuit.com/tax-tips/irs-tax-return/video-are-cash-back-rewards-taxable-income/L1FWH...

But keep in mind that a sign on bonus might be considered income if it is not contingent upon use of the card/account...

So along those lines, the Chase account sign on bonuses would be taxable because you don't have to spend anything to earn them:
https://thepointsguy.com/guide/are-bank-account-bonuses-taxable/

You might check the offer postcard for mention of the bonus being reported as 1099-INT income (if you don't have the original, you probably receive a new one every month in the mail like I do, lol).

Also, if you opt in for paperless statements, or if you have accounts with other banks which only do paperless, you may need to check your online account for the 1099-INT. The bank may (should?) notify you via email when paperless forms are available.