Many business owners put off switching because they expect weeks of admin and an awkward conversation. The detailed handover work is the new accountant's job.

Should you switch accountants?

The usual reasons for switching are slow replies, unclear advice, too much chasing and no view of the numbers between one year end and the next.

Ask whether your accountant helps you run the business or only files the paperwork. A good accountant files your returns on time and also tells you in January what your tax bill will be the following January, and what you can still do about it.

The five steps of a handover, and who does each one

You are involved in two of the five steps.

  1. You appoint the new firm. You sign an engagement letter setting out scope and fees, and complete anti-money-laundering identification. Every accountancy practice is required by law to verify your identity with photo ID and proof of address before acting. Your job. Twenty minutes.
  2. The new firm writes for professional clearance. This is a letter from your incoming accountant to your outgoing one asking whether there is any professional reason not to accept the appointment, and requesting handover information. It is standard practice under the professional codes of ethics, it happens between the two firms, and it is not a confrontation. You do not referee it. Their job.
  3. You authorise the new firm with HMRC. Either you sign a form 64-8, or you approve a digital request from the agent's HMRC agent services account with a couple of clicks from your own Government Gateway login. Authorisation is per tax — Corporation Tax, Self Assessment, VAT, PAYE — so check every tax you pay is covered. Your job. Ten minutes.
  4. The records move. Last filed accounts and the tax computations behind them, the trial balance and closing balances, payroll records and pension data, VAT history, capital allowances and fixed asset schedules, and control of the bookkeeping software. If you are on Xero or FreeAgent, the subscription and the adviser access get reassigned rather than rebuilt. Their job.
  5. The new firm reconciles and takes over the calendar. The new accountant should rebuild your deadline list — year end, Corporation Tax, confirmation statement, VAT quarters, payroll RTI, Self Assessment — and tells you what is due before you have to ask. Their job.

What delays a handover

Unpaid fees to your current accountant are the most common reason a handover stalls, because a firm is entitled to take a view on releasing certain documents while its account is unsettled. Check early whether anything is owed, and settle it or agree terms.

The second most common delay is an outgoing firm that does not reply. A good incoming accountant chases, and after a reasonable period proceeds on the information available from HMRC, Companies House and the last filed accounts. Ask how they handle a non-responsive predecessor.

Worked example: a September switch, and the cost of late filing

The company is illustrative; the penalties and interest rates are the real ones.

A Ballymena limited company with a 31 March year end decides on Monday 7 September 2026 to switch accountants. Accounts for the year ended 31 March 2026 are not started. The Corporation Tax for that year is payable on 1 January 2027 and the Corporation Tax return (CT600) is due by 31 March 2027. Estimated Corporation Tax: £20,000.

  • Day 1 — engagement letter signed, ID completed.
  • Day 2 — professional clearance letter goes to the outgoing firm.
  • Day 3 — 64-8 signed, or the digital authorisation approved online.
  • Day 12 — clearance response and records received.
  • Day 19 — records reconciled, deadline calendar rebuilt, draft accounts underway.
  • Mid-November — accounts and CT600 finalised, six weeks before the tax is due to be paid.

The switch takes roughly three weeks, of which the owner spends half an hour. If the company stays another year with a firm that files late, the costs are:

  • CT600 one day late: £200
  • Still late at three months: a further £200
  • Still late at six months: HMRC determines the tax and adds 10% of the unpaid tax — on £20,000 that is £2,000
  • Interest on £20,000 unpaid for six months at the current HMRC late payment rate of 7.75% (Bank of England base rate plus four percentage points, in force since 9 January 2026): about £775

That is £3,175 for one year handled badly, and it compounds: a third consecutive late return turns those £200 penalties into £1,000 each.

Changing accountant before your year end

You can switch at any point in the year. The process is the same whenever you start it.

You do not need to wait until your year end has passed. If the year has ended and the accounts are not started, the new accountant prepares them, as in the example above. If your current accountant is part-way through them, the two firms agree which of them finishes that year. For a company with VAT and payroll, the switch-over date is set so that no VAT return or pay run falls in the gap, and the year-to-date payroll figures move across.

Two points affect timing. If you are within about three weeks of a hard filing deadline, expect the incoming firm to deal with that filing first and tidy the handover afterwards. And if you are a sole trader or landlord inside Making Tax Digital for Income Tax, which began on 6 April 2026 for qualifying income over £50,000 and extends to over £30,000 from April 2027 and over £20,000 from April 2028, the handover now has to include the digital records and software access alongside the accounts. Our Making Tax Digital page sets out what that requires.

Switching accounting software when you change accountant

You can keep your accounting software when you change accountant. If you already use Xero or FreeAgent, the new firm takes over adviser access and you keep the full history.

If you do move to different software, your history stays. Opening balances come from your last filed accounts, and the old records stay where they are. You must keep them for at least six years. A straightforward migration takes about six weeks, including a parallel period in which the old and new systems both run, and it is best timed at a year end or a VAT quarter end. At Buzz, FreeAgent is included in the monthly fee, and so is moving your records across from your old system. Our accounting software page covers Xero and FreeAgent, and the digital switchover page gives the week-by-week timeline for moving from paper or a spreadsheet.

Switching contractor accountants

A contractor with a limited company switches in the same five steps, and can do it in the middle of a contract. Check two things first: the notice period in your current engagement letter, and whether work you have already paid for has been done.

At Buzz, a contractor's limited company starts at £49 + VAT a month, covering the accounts, the Corporation Tax return, VAT returns, the confirmation statement and your Self Assessment as a director. Our contractor accountants page covers IR35 and what the fee includes.

Questions to ask a new accountant

Ask these seven questions before you sign:

  • Who will actually do my work, and who do I email when something is urgent?
  • What is included in the fee, and what triggers an extra bill?
  • What will I get between year ends, and how often?
  • When will I know my tax bill — the month it is due, or the year before?
  • How do you handle it if my previous accountant does not respond?
  • Which software will I be on, and who owns the subscription?
  • Are you licensed and supervised, and by whom?

Buzz Accounting is an AAT licensed practice, licence number 1001556, and is supervised for anti-money-laundering purposes by HMRC.

Switching to Buzz

We manage the handover end to end: writing for clearance, chasing it, getting the authorisations in place, pulling the records across, and rebuilding your deadline calendar. You sign two things and answer the odd question.

We tell you the timescale before anything starts. A clean handover with responsive predecessors runs in two to three weeks. One involving several years of unfiled work or a firm that has gone quiet takes longer.

Switching to Buzz is free. The clearance letter, the HMRC authorisations and the software set-up are included when you join. Catch-up bookkeeping, where the books are behind, is quoted separately before any work starts. Accounts and tax start at £29 + VAT a month for a sole trader or landlord and £49 + VAT a month for a limited company. The steps for moving to us are on switching your accountant to Buzz.

See how we work with businesses like yours on our small business accounting page, work through the switching accountants checklist, or look at what is covered in our accountancy packages. Then get in touch and we will talk you through what switching would involve for you.