Greetings, es3.
It's nice to see you in the Community. I'm here with some insight to provide regarding the categorization.
Just to clarify, are you using QuickBooks Desktop (QBDT) or QuickBooks Self-Employed (QBSE)? If you're using QBDT, then you may consider it as Owner Equity since this version of QuickBooks has the Chart of Accounts feature.
However, if you're using QBSE which is mainly used for tracking Income and Expense transactions, then you may want to categorize it as income instead. For additional support regarding the categorization, I'd recommend reaching out to our AnswerXchange Community forum. They can help you select the category that will best match your commision.
That should get you going in the right direction. Please let me know if there's anything else I can do for you. Wishing you all the best!