🤔This may not work for everyone, however it did for me. If you don't have a Capital One account, create one online at CapitalOne.com. If you do have a current account, you'll use it. (Note: I didn't deactivate or close Discover on Quicken.) Open Quicken and click on the + at the top left above the account balances in the account bar. Search for this financial institution = Capital One Card Services. Use your Capital One sign-in. A box will pop up for you to authorize Quicken's access to your Discover account info through Capital One. Check the Discover box. You will then be returned to Quicken. Link to your existing Discover Card account on Quicken in the pop-up box. It will automatically update. Done. In the "account details" box for that account on Quicken, Discover was automatically replaced with Captital One.
As of today, Jan 26, 2026, the banking side of Discover hasn't yet moved but will not update through Quicken, however, the Discover sign-on still works to view your banking accounts and transactions online at Discover.com. ☺️