Can I use the checks we already have on quickbooks. They are 3 panel voucher checks with the check part on the bottom?

Greetings, @lmaggio.

I’m glad to see you in the Community today. I’d like to share a few details about using 3-panel voucher checks in QuickBooks Online (QBO).

Yes, you can use your available preprinted voucher checks in QBO. All you need to do is make sure the setup and the check type selected when printing is correct.  

You may start with selecting a check type and print a sample. Here's how:

1.    Choose Expenses from the left menu and choose Print Checks.
2.    Go to the Print setup at the bottom of the page.
3.    Select the type of checks you have.
4.    Load blank paper into your computer. 
5.    Click View preview and print sample button.

Now, place the sample on top of a blank check page to hold both of them up to the light. If the information lines up correctly, you can now print checks without further setup. If not, proceed to Method 2 which is to set up Adobe Reader. Check out this article for more information:  How to print checks.

You may also check out these article for reference, as well as screenshots and video tutorial in printing checks:

• Print Checks.
• Align preprinted checks for your printer.
• How to print checks.

In case you’ll need to purchase checks and supplies, visit our IntuitMarket. 

The information above should get you pointed in the right direction. Please let me know if you have questions or clarifications. I’ll be here to help. Take care and have a good day!