Hi, @Sm28o.

I understand how frustrating it can be when things take longer than expected. Your time is valuable, and it's not our intention to keep you waiting for a solution. I know adding signatures to checks is vital to your business and would help many customers as well. Let me share some updates about it.

Currently, this option is still unavailable in QuickBooks Online (QBO). As a valued QuickBooks customer, we'd love to have your input about the enhancements you'd want to see in QBO by sending feedback to our product developers. They can review your suggestions and consider adding them in future releases. You can do this by opening your QBO account, then clicking the Gear icon at the top and selecting Feedback. You can also utilize our Customer Feedback page.

Aside from looking for a third-party application, you can affix the signature manually on every check you’ve printed as a workaround.
 

Moreover, you can always visit our Help Articles page to look for helpful information that can guide you in achieving your tasks in QBO.

We genuinely appreciate your patience and understanding on this. If there's anything else you want answers with, feel free to post them down below. We'll be here ready to help.