Of course, I'd charge. It's your time. If you're going to work for free, take a vacation instead! Charge them your top hourly rate, plus a PITA fee (I tend to label it The CARES Act or something appropriate on the invoice). And, when they run payroll themselves in QB and call you with questions, charge them your top hourly rate, minimum one hour (or, if you're feeling generous, 15-minute increments) billed monthly. Don't forget to charge them for all the clean-up (bookkeeping on your invoice) you'll be doing for them before you can prepare their tax returns next year. Stop work when an invoice is unpaid. They are going to suck up your time, so start by charging them now. If they don't complain, raise your rates.