Most business owners decide to change bookkeepers in about March, when they see what last year’s books did to their return. Then they wait, because switching sounds like a project. By the time they act it is June, and the switch costs more than it needed to.
Here is why the timing matters more than the decision.
A mid-year switch means someone reconciles two half-years
When you move providers in June, your year has two sets of books kept two ways. Different charts of accounts. Different rules about what counts as an expense and when. Different opinions about what a transfer is.
Somebody has to make those two halves agree before a return can be prepared, and that somebody bills for it. You pay twice for one year of bookkeeping: once as it happened, once to make it consistent.
Switch at the year boundary and there is nothing to reconcile. The old provider closes a year. The new one opens a year. The seam falls where the seam belongs.
What a clean handoff actually needs
The work happens in November and December. By the time the new year starts, a good handoff is already finished. A handoff needs:
- A closed prior year. Not “mostly done.” Closed, with the bank and credit-card accounts reconciled through 31 December.
- Access, not exports. Direct access to the accounting file, so the new provider sees the history rather than a spreadsheet of it.
- The vendor file. Names, addresses, taxpayer identification numbers, W-9s on hand. This is the part that is always missing, and it is the part that has a January deadline attached to it.
- The payroll history, if payroll moves too. A payroll switch mid-quarter is its own separate mistake.
- Whatever the last provider was doing that nobody wrote down. There is always something. Ask for it in writing before the relationship ends, not after.
Gather that in November and the changeover itself is uneventful — the new provider starts work on a year that is already clean. Leave it until the new year has started and you spend a month chasing a firm that no longer works for you.
The vendor file is the deadline you cannot move
Most of a handoff can slip a few weeks without real cost. Vendor records cannot. Information returns for 2026 payments are due early in 2027, and you cannot file what you do not have. If your W-9s are incomplete, the person who finds out is whoever is preparing those forms in January, at the worst possible moment.
Worth knowing while you are in the file: for payments made in 2026 the 1099-NEC reporting threshold is $2,000, not $600. That is a real change, and it does not mean you can stop collecting W-9s — backup withholding rules are unchanged. We wrote about that here.
If you are thinking about it, decide in October
Not because of us. Because a provider who is going to take on your books in January needs to look at them in November, and every decent one is fully committed by mid-December. The owners who switch cleanly are the ones who made the call two months before the date.
We do monthly bookkeeping, payroll, and the tax work that sits on top of it, federal and state, in all fifty states. There is a named CPA on the file and your call gets returned.
This post is general information about federal and state tax rules, not advice about your situation. Rules change. Check the date above before you rely on anything here, and talk to us about your own facts.