Accountant Handoff Checklist for UK Sole Traders

A good accountant handoff comes down to three things: your records in one place, written authority for the new accountant, and a clear statement of what the old one has and hasn’t finished. Get those right and a switch, or a first appointment, takes days rather than weeks. Get them wrong and you can end up with a missed filing date that nobody owns.

This checklist is written for UK sole traders in the trades: plumbers, electricians, carpenters, builders. It covers what to gather, what to ask for, what to hand over, and the traps that cause disputes.

TL;DR

• Tell your outgoing accountant in writing that your new one may contact them, and ask for a disengagement letter showing what is finished and what is pending.
• Hand over a clean pack: ID details, previous returns, the current year’s income and expenses, CIS statements and mileage.
• Check for unpaid fees before you move. An accountant can hold back records over unpaid bills, so settle or resolve them first.
• Remember that you stay responsible for your tax, whoever files it. Keep your own view of income, expenses and profit.
• If your income is over £50,000, agree who handles Making Tax Digital before the handover date, not after.

Table of Contents

• Who this checklist is for
• Step 1: Check where you stand before you move
• Step 2: Give written permission both ways
• Step 3: Ask for a disengagement letter and status report
• Step 4: Build the handover pack
• Step 5: Do a quick sense check before you send it
• Step 6: Check your Making Tax Digital position
• What a good handover looks like on the day
• Our view: you still own the numbers
• Making the pack easy with TradeTally
• Common handoff mistakes
• FAQ
• Sources

Who this checklist is for

You might be using it in one of three situations:

1. You are moving from one accountant to another mid-year.
2. You have done your own Self Assessment so far and are handing it to an accountant for the first time.
3. You are tidying up before the end of the tax year so that whoever files your return gets everything first time.

The steps differ slightly, but the core pack is the same. Where the situation changes the advice, we say so.

Step 1: Check where you stand before you move

Before you contact anyone new, look at what you already have with your current accountant.

• Outstanding fees. An outgoing accountant may be able to keep your records under what ICAEW describes as a particular lien if fees are unpaid. That is meant to help recover bills from a slow payer, not to settle a genuine fee dispute, and the accountant is expected to take reasonable steps to resolve a dispute first. If you think a fee is wrong, say so in writing early.
• Work in progress. Is a return half-prepared? Are accounts drafted but not approved? Note it down. This feeds the status report you will ask for in step 3.
• Upcoming deadlines. The online Self Assessment deadline is 31 January after the tax year ends. If you are switching in the weeks before a deadline, agree in writing who is filing.
• Your own copies. Download your last accounts, tax returns and any HMRC correspondence while you still have access. ByteStart’s guide to switching accountants makes the same point about saving copies before you change.

Pro tip: Do not leave your old accountant until you have a date for the handover. A handover date should reflect unfinished work and upcoming reporting, not just the day you got fed up.

Step 2: Give written permission both ways

A lot of tradespeople think the new accountant needs the old one’s permission to take them on. They don’t. What happens is a professional enquiry: the incoming accountant is expected to ask the previous one about anything that might affect whether they accept the work, and the outgoing one should not stand in the way of a switch. The ICAEW helpsheet for incoming accountants sets out that enquiry.

What the outgoing accountant does need is your permission, preferably in writing, before they talk to the new one. The ICAEW helpsheet for outgoing accountants says they should obtain it. Your personal data is involved, so this is also a data protection point: your consent is what lets them pass files on.

So send two short messages:

1. To the outgoing accountant: you are changing advisers, you authorise them to respond to the new firm’s enquiry and to release your records, and you ask for confirmation of any outstanding fees.
2. To the incoming accountant: you have told the old firm, here is their contact, and here are the details they need.

Keep both in an email thread you can find again.

HMRC authority is separate

Permission between accountants is one thing. Your new accountant also needs authority from you to deal with HMRC on your behalf. HMRC offers an online route and a paper form, the 64-8. The new accountant will normally send you the request. If you want to check how it works first, HMRC explains it in its agent authorisation guidance on GOV.UK. Your old accountant’s authority should be ended at the agreed handover date so the two firms aren’t both acting for you.

Step 3: Ask for a disengagement letter and status report

This is the document most tradespeople never ask for, and it is the one that protects you most.

ICAEW’s guidance on disengagement letters explains the purpose: it clarifies which matters the outgoing firm remains responsible for during a handover, and which fall to you or the incoming accountant. In practice, ask for a letter that states:

• which tax years and filings were completed, and when;
• what is still outstanding, such as a return in draft or a pending HMRC query;
• the exact date their responsibility for your affairs ends;
• what records they are returning and what they are keeping, and why.

Without it, you risk a dead zone: the old firm thinks the new one has the January return, the new firm thinks the old one has finished it. HMRC will not care whose misunderstanding it was. Penalties land on you.

If the outgoing accountant doesn’t offer a letter, ask for one in writing. It is a reasonable request.

Step 4: Build the handover pack

Here is what a new accountant will typically ask a sole trader for. ByteStart’s list includes your UTR, National Insurance number, previous accounts and copies of your Self Assessment returns. For a tradesperson, we would build the pack in these groups.

Identity and HMRC details

• Unique Taxpayer Reference (UTR)
• National Insurance number
• Business name, start date and trade description
• VAT registration number, if you are registered
• Government Gateway access details, only if the accountant asks for them. Keep them secure and never send passwords in plain email.

Previous years

• Last two or three Self Assessment returns and the computations behind them
• Last year’s accounts, or your own summary if you file on a simple basis
• Any HMRC letters, notices of coding, penalty notices or open queries
• Payments on account made, with dates

This year’s income

• All invoices issued, paid and unpaid
• Bank statements for the account you run the business through
• Cash jobs, with a record of each one
• Grants or other business income if you received any

GOV.UK says you must keep records of all sales and income, and all business expenses, plus VAT records if you are registered and PAYE records if you employ people. That list is the minimum your accountant is working from.

This year’s expenses

• Receipts for materials, tools, workwear, insurance, phone and software
• Van or vehicle costs, or a mileage log if you claim by mileage
• Subcontractor payments, if you pay others
• Any home office or use-of-home figures

If your receipt pile is a carrier bag in the footwell, step 6 is for you. Our expense tracking guide for sole traders shows how to sort expenses so they map to the categories on the return.

CIS records

If you work as a subcontractor under the Construction Industry Scheme, your accountant needs:

• every payment and deduction statement from each contractor
• a total of deductions suffered in the year
• a note of any months with a missing statement

Missing statements are the single most common reason a tradesperson’s return is delayed. Chase them from contractors before the handover, not after.

Mileage and time

• A log with date, journey purpose and miles
• Any records of time spent on jobs that you charge by the day or hour

Step 5: Do a quick sense check before you send it

A clean pack is worth more than a big one. Before you send it, run through these:

1. Do invoices issued match money received in the bank, or are the gaps explained?
2. Is every expense backed by a receipt or invoice, or noted as missing?
3. Are personal and business transactions separated, or marked?
4. Does the total of CIS deductions match your statements?
5. Are there any jobs started but not invoiced? Your accountant needs to know about work in progress.

Pro tip: Send a one-page cover note listing anything odd: a big one-off purchase, a client who hasn’t paid, a new van. It saves the accountant a round of questions and often a fee.

Step 6: Check your Making Tax Digital position

This is where timing matters. According to GOV.UK, sole traders and landlords with qualifying income over £50,000 must use Making Tax Digital for Income Tax. The threshold is based on gross turnover, before expenses, from your previous tax year’s return. The same guidance says it drops to £30,000 from 6 April 2027 and £20,000 from 6 April 2028.

If you are in scope, you or your agent must use software that works with MTD to keep digital records and send quarterly updates. The GOV.UK guidance on digital records says you must also continue keeping records as you normally do for Self Assessment, including original paperwork where needed.

For the handoff, that means agreeing three things in writing:

• Who signs you up. The sign-up process requires you to be registered for Self Assessment and to have submitted a return in the last two years, among other conditions.
• Which software holds the records. If your new accountant uses their own, find out how your day-to-day invoices and receipts get into it. If you keep your own records, check that your software can meet the requirements GOV.UK lists.
• Who does the quarterly updates. Your accountant, you, or a shared arrangement.

If you want a wider look at what can be automated around this kind of admin, the small business automation checklist for UK owners is a useful prompt list. For our own MTD material, start with the six steps to be ready for MTD and the page on MTD requirements for mobile setup.

What a good handover looks like on the day

By the agreed date, you should be able to tick every line below.

Our view: you still own the numbers

This is our perspective, written from the side of someone who does the work on site and the paperwork afterwards.

Handing over to an accountant is a good move for most tradespeople. But it is easy to take it as handing over the thinking too. Government guidance on business accounting says an accountant can help you stay compliant and spot tax-efficient options, but responsibility for compliance stays with you.

So we build TradeTally around a simple idea: you should always know what you have invoiced, what you have spent and roughly what profit you are sitting on, without waiting for a year-end phone call. When your records are tidy and live, a handover is a ten-minute export rather than a weekend with a shoebox. A switch stops being frightening, because nothing important lives only in someone else’s filing system.

That is also why we think the best handover starts months before you change anyone. Keep invoices in one place, photograph receipts the day you get them, and your accountant, old or new, spends their time advising rather than sorting.

— Simon

Making the pack easy with TradeTally

If your records are the weak link, TradeTally is built for that. You can create branded invoices, snap receipts from the van, track mileage and time, handle CIS deductions, and export records formatted for SA103F, the self-employment page of the Self Assessment return, so your accountant receives them in a form they can use. The Starter plan is £0 per month, and the Professional plan is £12 per month or £120 per year. You can see the details on our pricing page, or start from the TradeTally homepage.

For more on the end-of-year side, our own accountant handover checklist with SA103F export goes through the export step by step, and the free sole trader tax and CIS checklist is a quick way to see what you are missing.

Common handoff mistakes

• Leaving on bad terms with fees unresolved. It gives the old firm a reason to hold your files. Settle or dispute in writing first.
• Skipping the disengagement letter. Then nobody can say who owned a filing.
• Sending raw bank statements and nothing else. The accountant then bills time for guessing which payments are income.
• Forgetting CIS statements. Chase them early.
• Assuming MTD is the accountant’s problem. The threshold is based on your turnover, so you need to know if you are in scope.
• Not keeping your own copy. Always download before access ends. How long you must keep records depends on your situation, and our five-year records checklist covers it.

FAQ

Can my old accountant refuse to hand over my records?

They cannot block the switch itself. They may, however, hold back some records through a particular lien if you owe fees, though ICAEW says they should take reasonable steps to resolve a genuine dispute first. If this happens, put your side in writing and ask your new accountant to help.

Will I be charged for the transfer?

There is no standard charge for transferring records. Outgoing accountants may charge for significant extra work, such as retrieving years of archived files or preparing information you should already have received. Ask for an estimate before you agree to anything.

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

Yes. Mid-year switches are common, but agree the handover date and who files what before you move. A disengagement letter and status report make the split clear.

What if I have never used an accountant before?

The same pack applies, minus the professional enquiry and disengagement letter. Gather your UTR, previous returns, income and expense records, and CIS statements, then give your accountant HMRC authority so they can act for you.

Sources

• Use Making Tax Digital for Income Tax: introduction, GOV.UK
• Create digital records for MTD for Income Tax, GOV.UK
• Sign up for Making Tax Digital for Income Tax, GOV.UK
• Choose the right software for MTD for Income Tax, GOV.UK
• What records to keep, GOV.UK
• Setting up business accounting and finance, Business.gov.uk
• Change of professional appointment: incoming accountant, ICAEW
• Change of professional appointment: outgoing accountant, ICAEW
• Disengagement letters, ICAEW
• How to switch accountants as a sole trader, ByteStart

Recommended

• Free UK Sole Trader Tax & CIS Checklist
• Store Records 5 Years: Self Assessment Checklist for UK Sole Traders
• Expense Tracking Guide UK for Sole Traders