If the firm is only acting as an agent to file the return and you issue the statement, then the tax check is in accordance with your statement
If the firm is also helping to act as an agent to keep the books, the tax check is of course in accordance with the accounting firm's first hand
The problem is that if the tax office finds out that you provide a different statement from the one declared by the tax office, then there is something wrong with it.
Take as much tax as you have income. Doing your books without considering taxable income poses a significant tax risk.
Suggest you ask a tax preparer or an accountant friend to take a look for you!
Hope it helps you!!!!