Short answer: It depends on the firm. Plenty of bookkeepers stop at the financial statements and hand you off to a separate tax preparer. We handle both, which means the return is built from books we already know are right.
The distinction is worth understanding, because it is where a lot of money quietly goes missing.
Bookkeeping is the ongoing work: categorizing, reconciling, closing the month, producing statements. Tax preparation is the annual work of turning those statements into a filed return. They are different jobs, and in many small businesses they are done by two parties who never speak to each other.
That handoff is the expensive part. The tax preparer receives a file they did not build, finds problems in it, and either sends back a list of questions in March or makes assumptions to get the return out. Neither is good. The questions cost you weeks at the worst possible time, and the assumptions cost you deductions, because a preparer who cannot tell what a transaction was will code it the safe way rather than the right way.
When the same people keep the books and prepare the return, that gap closes. Questions get resolved in June when they are easy, not in April when they are urgent. Deductions get captured because someone knew what the transaction was at the time.
A note on scope: we handle personal and business returns and year-round planning. If your situation needs a CPA’s attestation — an audited financial statement, for instance — that is a different credential and we will tell you plainly rather than stretch.
Related: What does a bookkeeper actually do each month? · Bookkeeper vs. accountant vs. CPA · Tax Planning & Preparation