Good day, useraerie4354.
Let's correct the posting account of the Check in your QuickBooks Online (QBO).
You can open the check and change it to the correct Bank Account. I'll walk you through how to do it:
- Go to Expenses and choose Vendors.
- Select the vendor who has the check.
- Locate the check you want to correct.
- Open the Check and update the Bank Account to the correct one.

Another way to locate the check is through the search option.
Here's how:
- Select the magnifying glass icon at the top of the page.
- Search for the transaction by entering a transaction number, a date, or an amount and selecting Enter.
- Open the Check and edit it from there.
For your guide on how to reprint a copy of your checks in QBO, here's an article you can visit: How to reprint checks and sales forms.
You can also run the Check Detail report to review the checks made. Do this by going to the Report menu and enter the Check Detail.

If there's anything I can help you with while working with checks, feel free to drop me a reply below. Hope you have a good one.