If your accountant is slow to reply, vague on price, or only surfaces once a year to file something, you don't have to put up with it. Changing accountants is far simpler than most business owners fear, and you do almost none of the heavy lifting.
The good news is that the bulk of the work, the paperwork and the chasing, is handled between your old firm and your new one. Your job is mostly to say yes, sign a couple of things, and prove who you are.
This guide walks you through exactly how to change accountants in the UK: the steps, the timeline, the best time of year to do it, and the handful of things that genuinely are your responsibility. It's written for sole traders, contractors and limited company directors who want a clean switch with no drama.
Can you change accountants whenever you want?
Yes. There's no contract with HMRC that ties you to a particular firm, and switching is a routine thing that accountants deal with all the time. You're free to move at any point in the year.
Check your engagement letter first, though. Most firms ask for 30 days' notice or have a notice clause, and some bill for work already in progress up to your leaving date. Honour that and the parting stays friendly, which makes the handover quicker.
You don't need to tell HMRC the reason, and you don't need your old accountant's permission to leave. You simply appoint a new firm and let the professionals sort out the rest.
How do you change accountants step by step?
In practice, a clean switch comes down to five steps. Most of them happen behind the scenes once you've picked your new firm.
- Choose your new accountant. Confirm what's included, what it costs, and how they communicate. Get the fee in writing before you commit.
- Sign the engagement letter. Your new firm sends a letter setting out the service, start date, fees and terms. Signing it makes the appointment formal.
- Pass the anti-money laundering checks. By law, your new accountant must verify your identity, so expect to provide photo ID such as a passport or driving licence plus a recent proof of address.
- Notify your current accountant. A short email or letter telling them you're moving, and that your new firm will be in touch, is usually enough. Settle any outstanding fees so they release your records promptly.
- Let the two firms handle clearance and handover. Your new accountant writes to the old one for professional clearance and your records, and sorts out the HMRC authorisation. You can largely step back at this point.
That's it. You're not expected to broker the conversation between the two firms or move files around yourself.
What is a professional clearance letter?
A professional clearance letter is the formal note your new accountant sends to your old one before taking you on. It's a long-standing professional courtesy in the UK accountancy world, and members of bodies like the ICAEW and ACCA are expected to do it.
The letter asks two things. First, whether there's any professional or ethical reason the new firm shouldn't act for you, for example an unresolved dispute. Second, it requests copies of the information the new firm needs to pick up your affairs cleanly.
Your previous accountant should reply promptly and shouldn't withhold the underlying books and records that belong to you. Be aware of one nuance: a firm can sometimes hold on to documents they've produced if you still owe them money, which is called a lien. Clearing any outstanding invoice removes that obstacle, so it's worth doing early.
How do you change your tax agent at HMRC?
Appointing your new accountant as your agent is what lets them file returns and speak to HMRC for you. There are two routes, and your new firm normally drives this for you.
The faster route is the digital handshake: your accountant sends an authorisation request through their HMRC agent account, and you approve it from your own Government Gateway. The traditional route is the paper form 64-8, "Authorising your agent", which you sign and HMRC processes by post.
Helpfully, you don't have to fire your old agent first. According to HMRC's guidance, "If you want to change the tax agent you have authorised, you must submit a new authorisation request. Any new authority received will replace any existing authority." So the new authorisation generally supersedes the old one for that tax.
You can also remove an old agent yourself through your HMRC business tax account if you'd rather tidy it up. Go to Manage account, then "Add, view or change tax agents", pick the tax and choose to remove the agent. One thing that never changes hands: you're still legally responsible for your own tax, so always check returns before they're submitted in your name.
When is the best time to switch accountants?
The smoothest time to move is usually just after your financial year-end, once the previous year's accounts are done. Handover is cleaner because there's a natural full stop in your records, and your new firm starts with a tidy opening position.
That said, timing shouldn't trap you. If your current accountant is missing deadlines or making mistakes, waiting can cost you more than switching mid-year. A good firm can take you on at any point and slot into your existing records.
Try to avoid the busiest crunch points if you can. The run-up to the 31 January Self Assessment deadline and the pre-Christmas wind-down are when accountants have the least spare capacity, so a switch then can feel slower at both ends.
How long does it take and what does it cost?
Switching itself is usually free. Your new accountant doesn't charge you to request clearance, and a reputable firm won't penalise you for moving to them. Your only likely cost is settling any work your old firm has already done up to your leaving date.
On timing, expect the handover to take a couple of weeks to a month in normal conditions, mostly down to how quickly your previous accountant responds. You can speed it up by paying any final invoice and replying to your new firm's ID requests the same day.
| What you might pay | When it applies |
|---|---|
| Nothing for the switch itself | Standard for reputable firms taking on a new client |
| Final fees to your old accountant | Work done or in progress up to your leaving date |
| New firm's ongoing fee | Per your new engagement letter, from the agreed start date |
What records should you get from your old accountant?
You want enough to give your new firm a clean starting point and to keep your own files complete. Ask your old accountant (or have your new one request) the following:
- Your most recent finalised accounts and the supporting trial balance
- Filed tax returns and computations (Self Assessment and, for companies, Corporation Tax)
- Capital allowances and fixed asset records, including pool balances carried forward
- VAT returns and workings if you're VAT registered
- Payroll records and any PAYE details if they ran your payroll
- Your tax references: UTR, company number and VAT number where relevant
Keeping these is also part of staying compliant. HMRC expects you to retain business records, and a complete handover means nothing slips through the gap between two firms.
Illustrative example: a contractor mid-year switch
Illustrative example. Tom is a limited company contractor with a 31 March year-end. In May 2026, two months into the 2026/27 tax year, his current accountant has gone quiet and missed a couple of his emails. He decides not to wait until next year-end.
Tom signs his new firm's engagement letter, sends a photo of his passport and a recent utility bill for the anti-money laundering check, and emails his old accountant to say he's moving. He settles a small outstanding invoice the same week, which clears any lien over his records.
His new accountant sends the professional clearance letter, requests his latest accounts, Corporation Tax computation and pool balances, and fires off a digital authorisation request to HMRC. Tom approves it from his Government Gateway in a couple of minutes. Within about three weeks the records are across and his new firm is fully authorised, all without Tom having to file or move anything himself.
Note that this is a worked illustration to show the flow, not a real client. The figures and dates that matter to your own tax should always come from your records and current HMRC guidance.
Frequently asked questions
Do I have to tell HMRC I'm changing accountants?
Not directly. You authorise your new accountant as your agent, and that new authorisation replaces the old one. You can also remove a previous agent yourself through your HMRC business tax account if you want to keep things tidy.
Will changing accountants trigger an HMRC enquiry?
No. Switching accountants is routine and is not a trigger for an enquiry. HMRC processes thousands of agent changes, and moving firms is a normal part of running a business.
Can my old accountant refuse to hand over my records?
They shouldn't withhold the books and records that belong to you. They can, however, hold on to documents they've produced if you still owe them fees, which is called exercising a lien. Paying any outstanding invoice removes that issue.
How much notice do I need to give my current accountant?
Check your engagement letter. Many firms ask for around 30 days' notice and may bill for work already in progress. Giving proper notice keeps the relationship civil and the handover fast.
Is there a best time of year to switch?
Just after your year-end is usually smoothest, because the previous year is finalised. But if your accountant is letting you down, switching sooner is normally the better call. Try to avoid the January Self Assessment crunch if you have a choice.
Do I still need to check my tax returns after I switch?
Yes. Even with an agent acting for you, you remain legally responsible for your own tax. Always review a return for accuracy before it's submitted in your name.
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Ready to make the switch?
Thinking about moving but not sure where to start? We handle the professional clearance, the records request and the HMRC authorisation for you, so the switch is genuinely off your plate. Whether you're a limited company, a sole trader or a contractor, we'll get you set up cleanly and explain exactly what we'll do next.
Book a free, no-obligation call with a Zmartly accountant and we'll map out your switch. We can also take over your day-to-day bookkeeping, your year-end statutory accounts, and give you proper tax advice once you're on board.
