Glad to see you here in the Community, ellen. I can help you combine two credit cards under one account.

Yes, you can merge them under one account, but you need to know that once you merge your bank account, you're unable to undo them. When you merge an account, all the data moves into the one you want to keep and removes the duplicate. Also, if the account has reconciliation reports, make sure you've saved them. This way, transactions remain on the merged account and stay reconciled.

Here's how:

1. Go to the Accounting menu on the left navigation bar.
2. Select Chart of Accounts.
3. Locate the account you want to keep. Then, click the drop-down arrow next to View register and select Edit.
4. Take note of the account details and click Cancel.
5. Look for the account you want to merge. Then, click the drop-down arrow next to View register and select Edit.
6. Change the duplicate account's info to exactly matches the account you want to keep and click Save.
7. When you're ready, select Save and then Yes, merge accounts.

You can refer to this article for more detailed steps: Merge duplicate accounts, customers, and vendors in QuickBooks Online.

I've also added this article for your guide in reconciling your account in the future: Learn the reconcile workflow in QuickBooks.

Ping me a reply if you need any additional information or clarification about merging your bank accounts. I'll get back to you as soon as possible. Advance Happy New Year, and I wish you well!