The accountant we changed halfway through the year

Almost nobody leaves their accountant over price. They leave over silence — the emails that take nine days, the question that gets answered with another question, the year-end accounts that arrive eight months after the year ended and tell you what happened rather than what to do.

And then they stay anyway, for another two years, because of a belief that is almost universal and completely wrong: that you have to wait until the year end to move.

You do not. You can change accountant on any day you like. But changing mid-year has a sequence, and getting the sequence wrong is how a filing gets missed by two firms who each assumed the other had it.

What actually happens, in order

Read your engagement letter first. It sets out the notice period and how fees are handled on termination. Most are a month; some bill annually in advance and refund nothing; a few charge for the handover itself. Whatever it says, you want to know before you make a decision, not after.

Appoint the new firm. You do not resign first. You engage the new accountant, sign their letter of engagement, complete their identity checks, and let them run the process. Doing it the other way round leaves you unrepresented for however long the search takes, which is precisely when a deadline slips.

They write for professional clearance. This is the formality that makes the whole thing civilised. The new accountant writes to the old one asking whether there is any professional reason not to act, and requesting the handover information. You will be asked to authorise the outgoing firm to respond, because they cannot release your information without your say-so. It is routine and it is not a negotiation — the old firm is not being asked to approve your decision.

Records and information come across. What should arrive is more than a bundle of PDFs: the last set of finalised accounts and the tax computations behind them, the trial balance and closing balances, capital allowances pools, the fixed asset register, the directors' loan account history, VAT workings, payroll year-to-date figures and RTI submissions, any P11D history, and the software login or ownership.

Re-authorise the agent with HMRC. New authorisation for the new firm does not automatically strip the old one. Your previous accountant may retain access to your HMRC records until you remove them, which people discover much later and dislike. Removing an agent's authorisation is a specific action you take through your HMRC online account, and it belongs on the checklist.

Check who owns the software. If your bookkeeping subscription sits under the old firm's partner account, the data is yours but the subscription is theirs. Move billing into your own name before anything else happens, and confirm you have full admin access rather than a user seat.

The handover is not the accounts. It is the workings behind the accounts. A firm that sends a PDF of the last accounts and nothing else has not handed anything over.

The two traps

The lien. If you owe the outgoing firm money, they may be entitled to exercise a lien over papers in their possession that they have worked on, and hold them until the bill is settled. It is a real and long-established right, not a bluff, and it does not extend to everything — but it can slow a handover to a stop at the worst possible moment. Settle the account, or agree the dispute separately, before you expect a clean transfer. Some of what you need can be pulled from elsewhere in any case: filed accounts sit at Companies House, and submitted returns and liabilities sit in your own HMRC account, which you control.

The gap in the middle. A mid-year switch creates a period each firm can assume belonged to the other. The single most useful email you will send is the one that says, in writing, exactly which filings the old firm is completing and which the new one is picking up, with dates. Send it to both. It takes ten minutes and it is the entire difference between a tidy transition and a £100 penalty followed by an argument about whose it was.

The months not to do it in

Timing is everything and the calendar is unhelpfully full. A private company's accounts are due at Companies House nine months after the year end; corporation tax is payable nine months and a day after it, with the return due within twelve months; Self Assessment lands on 31 January, with the second payment on account on 31 July. Why your January tax bill is bigger than you expected explains that second one.

Making Tax Digital for Income Tax has added a new rhythm on top. Since 6 April 2026 it applies to sole traders and landlords with qualifying income over £50,000, with the £30,000 band following in April 2027 and £20,000 in April 2028. Quarterly updates are due on 7 August, 7 November, 7 February and 7 May.

Which gives you a practical rule: switch in the fortnight after a quarterly update has been filed and well clear of a year-end deadline. Late spring and early summer are usually clean. December and January are the worst possible choice, and the firm you are leaving will be least responsive in exactly those weeks.

What it costs

Expect an overlap. Illustratively: the outgoing firm was £150 a month and completes the year already in progress; the new firm is £220 a month and starts immediately on the current period and the quarterly filings. For a couple of months you are paying both, plus perhaps a one-off fee to bring the bookkeeping to a standard the new firm will work from — because the most common finding on any handover is that the last few months are not as reconciled as everyone assumed.

Set against that, be honest about what the old arrangement was costing in ways that never appeared on an invoice: decisions made late, a tax planning conversation that never happened, hours spent chasing.

What to ask before you sign the new one

Who does the actual work, and will you speak to them or to a partner you meet once a year? What is the turnaround commitment, in days, for a question by email? What is included, precisely, and what triggers an extra bill? What software, and whose name is the subscription in? How many businesses like yours do they act for? And the one that separates advisers from filers: when do they contact you, other than to ask for records?

If the answer to the last one is that they will contact you when the accounts are ready, you have found the same relationship you are leaving, at a different price.

The rest of the file matters too. Whoever holds it needs to be the person who answers the phone if HMRC opens an enquiry — the compliance check that started with one question is why that answer needs to arrive quickly rather than eventually.

Common questions

Can I change accountant in the middle of a tax year?

Yes. There is no requirement to wait for a year end, a quarter end or an anniversary, and the profession has a standard process — professional clearance — designed to make a mid-year move orderly. What matters is the sequence: read your engagement letter for the notice period, engage the new firm first, let them write for clearance, and then confirm in writing to both firms exactly which filings each is responsible for and by when. The realistic constraint is not permission but timing. Avoid switching within a few weeks of a filing deadline, and avoid December and January altogether, when both firms are at their busiest.

What is professional clearance and do I have to do anything?

It is the letter your new accountant sends to your old one asking whether there is any professional reason they should not act, and requesting the information needed to take over. Your involvement is small but necessary: the outgoing firm cannot release your information without your authority, so you will be asked to confirm in writing that they may respond. It is a professional courtesy between firms rather than a veto — the old accountant is not being asked whether they agree with your decision. If clearance goes unanswered for a couple of weeks, chase it yourself, because a polite email from the client usually moves faster than a second letter from a competitor.

Can my old accountant refuse to hand over my records if I owe them money?

Possibly. Where fees are outstanding, an accountant may be entitled to exercise a lien over papers in their possession that they have worked on, holding them until the bill is settled. It is long-established and it is not a bluff, so the practical answer is to settle the account or resolve the dispute on its own terms rather than letting it block the handover at a bad moment. Meanwhile, a surprising amount is recoverable without them: filed accounts are public at Companies House, and submitted returns, liabilities and payments sit in your own HMRC online account. Keep your own copies of everything from here on.

Does changing accountant increase the risk of an HMRC enquiry?

No. A change of agent is an administrative update and is not itself a trigger for a compliance check. The real risk in a switch is duller and much more common: a filing falling into the gap between two firms who each assumed the other was handling it, which does attract penalties and does draw attention. Close that gap with a single written confirmation to both firms listing every upcoming return and who owns it. Then remove the old agent's authorisation from your HMRC account, confirm the new one is showing correctly, and check the first return after the move against the previous year before it is submitted.