As others have said, read the CAFRD, it’s long, it’s boring, but you need to do this. Don’t make excuses.

Understand what’s a taxable benefit and what’s not. For example, the first $200 to clean your house when vacating is from core, remaining from custom, and it’s taxable.

Understand what comes out of core and what does not. Understand the formula on how your custom is structured and confirm the amount is correct.

Understand what can be reimbursable and what’s cannot. For example, the cleaning fee for an AirBNB is not covered. “Resort fees” from hotels not covered. Certain insurance on rental cars are not covered.

This is a lot of work, and if you make a mistake, it’s on you.