The big issue may not be your income tax liability, but obligation to declare all worldwide bank accounts and assets (shares, savings, real-estate, cars etc) and/ or be invoicing/ earning/ repatriating funds in the correct manner depending on your employment relationship. Failure to do these things can result in fines larger than the account balance... Anyway FY21 returns are due in June 22 I think, so time to consult a professional. Remember the statue of limitations is 10 years for non-registered tax payers and only 5 years for those registered.
