SEISS are to be taxed on receipt basis. Clients may give us the information. Sometimes this may not be the correct amount. Where such errors occur, for example in State Pension, we are able to cross check the numbers on HMRC's portal, " Information to help you complete your tax return". Similar errors can happen for SEISS. One way is to review the bank statements where the Accounting Year is not same as the Tax Year or review the bank transactions on cloud Accounting software with bank feeds . I was wondering if readers may know any other way to cross check. Thank you in advance for your time and suggestions.