CAN you use your personal bank account? Yes. There’s no law that says you can't, especially as you're operating as sole proprietor.

SHOULD you? Absolutely not. If you're serious about being in business, get serious about accounting for your business expenses and transactions properly by having a separate business account.

It can also save you money on accounting fees, as you'll save your accountant time and frustration trying to parse out your business from your personal expenses.