Where do you notate what check number was written to a vendor

Hi there.

You can notate the check number written to your vendor by turning on the Custom Transaction Number and entering a check number in the appropriate field. Let me walk you through the process.

Here's how to turn on the custom transaction number:

1. Click the Gear icon and select Account and Settings.
2. On the Sales tab, click Sales form content. 
3. Ensure that the Custom transaction number is enabled.
4. Click Save.

Then, we can start assigning check numbers to your checks. Open or create a new check transaction, and find the Check No. field to enter your check number.

Furthermore, you can also consider printing a report in check number order in QuickBooks Online.

We're always here to assist you if you have further concerns about writing checks in QuickBooks Online. Please feel free to leave a reply, and have a great day!