Good day, @SStone4203,

Commissions can either be revenue or an expense. If those checks are given to you for obtaining sales, it is an income on your books.

To account for this entry, create a service item called Commission Earned and select an income account for it. Use a generic client, or create the issuing company as a customer. Here's how:

1. Go to the Sales menu, then Products and Services.
2. Click on the New button and select Service.
3. Enter the name and all other information on the item set up.
4. Select a Commission Income Account.
   
5. When done, hit Save and close.

Use it on a sales receipt once you get the commission. Follow the steps below:

1. Tap on the Create (+) icon at the top-right section of the Dashboard.
2. Pick Sales Receipt from the list and manually fill out all necessary data.
3. Save the transaction once completed.
   

If you have any follow-up questions or need further help, please let me know in the comment section below. I'll be glad to help. Have a nice day!