I accidentally printed on checks that were in the printer instead of plain paper. How can I put these check numbers in the register as voided?

Good morning, @rudi-orourke.

I'm here to provide clarification with voiding those check numbers in your register.

Here's how to record a voided check in QuickBooks Online:

1. Choose the Plus + icon.
2. Under Vendors, select Check.
3. These are the following fields that must be completed (other fields are optional):

• Check number
• Payment date
• Bank Account
• Account

      4. Click on More, then Void.

      5. When "Are you sure you want to void this?" prompts, go to Yes.

Here is also a detailed article with some additional information about checks in QuickBooks Online as well: How To Void or Delete a Check in QuickBooks Online

Thank you for reaching out to the Community. Let me know if the steps above do the trick. Have a safe and productive rest of your week!