If you’re a sole trader trying to decide whether to hire an accountant, the first question is always the same: how much is this going to cost me? The answer is less vague than most articles make it sound. UK accountant fees for sole traders fall into clear ranges based on what you need — a one-off Self Assessment, ongoing bookkeeping, or full limited company services — and knowing the going rate before you ask for a quote puts you in a much stronger position.
This guide breaks down exactly what accountants charge in the UK in 2026, what affects the price, and when the cost pays for itself in saved tax and avoided mistakes.
How Much Does an Accountant Cost for a Self Assessment?
A one-off Self Assessment tax return prepared and filed by a qualified accountant costs £150–£500 for a sole trader. The price depends almost entirely on how complex your return is:
| Complexity | Typical cost | What’s included |
|---|---|---|
| Simple (one income source, trading allowance or basic expenses) | £150–£250 | Return preparation, filing with HMRC, basic tax calculation |
| Moderate (2+ income sources, property, some reliefs) | £250–£400 | Return preparation, filing, expense review, relief claims |
| Complex (multiple years, capital gains, foreign income, amendments) | £400–£800+ | Full return, multi-year filing, HMRC correspondence, tax planning advice |
The lower end of the range — £150–£200 — is what most sole traders with a single business and straightforward expenses should expect to pay. If an accountant quotes £500+ for a simple return, you’re overpaying.
How Much Is an Accountant Per Month?
If you want ongoing support — not just a one-off return — most accountants offer a monthly retainer. This typically includes bookkeeping, the annual Self Assessment, and advice throughout the year.
| Service level | Monthly cost | What’s included |
|---|---|---|
| Sole trader (bookkeeping + annual return) | £50–£150/month | Bank reconciliation, expense tracking, annual Self Assessment, basic tax queries |
| Limited company (accounts, CT600, payroll) | £100–£250/month | Bookkeeping, annual accounts, Corporation Tax, director payroll, dividend administration |
| Complex company (VAT, CIS, multiple directors) | £200–£400/month | Everything above plus VAT returns, CIS deductions, multi-director payroll, tax planning |
The retainer model makes sense if you want someone to call when you have tax questions, or if you’re above the MTD £50,000 threshold and need help with quarterly updates from April 2026. If you just want a return filed once a year, the one-off fee is better value.
Limited Company Accountant Costs
If you’ve incorporated or are thinking about it, the accounting costs are higher because the compliance burden is greater. A limited company needs:
- Statutory accounts filed with Companies House
- Corporation Tax return (CT600) filed with HMRC
- Director payroll (if you pay yourself a salary)
- Dividend administration and documentation
- Confirmation statement (annual return to Companies House)
Expect to pay £800–£2,500/year for a limited company accountant, depending on whether you need VAT returns, CIS, or multiple directors. The monthly retainer model (£100–£250/month) is standard here — very few accountants offer one-off limited company filing because the ongoing obligations make it impractical.
For a detailed breakdown of when incorporation makes financial sense, see our guide on sole trader vs limited company.
What Affects the Price?
Five factors determine where you fall in the ranges above:
1. Number of income sources
One income source (a single sole trade) is the cheapest to process. Each additional source — rental property, dividends, foreign income, CIS deductions — adds a separate section to the return and requires its own expense and relief calculations. Most accountants charge £50–£100 per additional income source.
2. Turnover and transaction volume
Higher turnover usually means more transactions to categorise and reconcile. If you have 500 bank transactions a year, the bookkeeping takes longer than if you have 50. Some accountants price on transaction volume rather than a flat fee.
3. Whether your records are organised
If you hand your accountant a shoebox of receipts and a year of unsorted bank statements, expect to pay more — some accountants charge £50–£100/hour for “record cleanup.” If you use accounting software and hand them clean, categorised records, the fee is often lower because their time is reduced.
4. Region
London and the South East are typically 20–30% more expensive than the rest of the UK. A £200 Self Assessment in Leeds might cost £250–£300 in London. Online accountants (who don’t have local office overhead) often charge the same regardless of where you are.
5. Whether you need advice or just filing
Filing-only services are cheaper. If you want ongoing tax planning advice — should you incorporate, how to structure pension contributions, how to handle benefits in kind — expect to pay a retainer rather than a one-off fee.
The Cheaper Alternative: Online Tax Return Services
If a traditional accountant feels too expensive, there’s a middle option. Online tax return services like TaxScouts, Untied, and 1TapTax charge £100–£300 per return and employ qualified accountants who file your return for you. They’re cheaper because the platform handles intake and workflow, reducing the accountant’s time per return.
The trade-off is less ongoing advice — the relationship ends when the return is filed. For a full comparison of services, prices, and what each one includes, see our comparison of UK tax return services.
For the three-way comparison — software vs online service vs traditional accountant — see our tax return service vs accountant vs software guide.
The Cheapest Option: Accounting Software + DIY
If your return is simple (one income source, trading allowance or basic expenses), you don’t need an accountant at all. Accounting software costs £10–£40/month and handles record-keeping, bank feeds, and — for MTD-compatible tools — quarterly updates. You still file the return yourself, but the software does the number-crunching.
FreeAgent (10% off with this link) is free if you bank with NatWest, RBS, or Mettle, and is one of the most popular options for UK sole traders. Account OS (AI accounting for UK micro-businesses) is another option for very small businesses with simple needs. For the full list of free and cheap options, see our cheapest MTD software guide.
If you want to file yourself for free with no software, HMRC’s online filing service costs nothing and takes 20–40 minutes for a simple return. Our first-year self-employed checklist walks you through it step by step.
When Does an Accountant Pay for Itself?
The cheapest option isn’t always the cheapest option. Here’s what’s at stake:
- Missed reliefs: A higher-rate taxpayer not claiming pension tax relief at the higher rate loses 20% of their pension contributions in unclaimed relief. On a £10,000 contribution, that’s £2,000 — more than any accountant’s annual fee.
- Wrong expense method: Choosing actual expenses when the trading allowance would save more (or vice versa) can cost hundreds. The right choice depends on your actual expense ratio.
- Late filing penalties: A missed deadline starts at £100 and escalates to £1,600+ for 6+ months late. An accountant who files on time costs less than a single penalty.
- MTD non-compliance: From April 2026, if you’re above the £50,000 threshold and not using MTD-compatible software for quarterly updates, you’ll face penalty points.
A £200 accountant who finds £2,000 in missed reliefs saves you £1,800 net. A £0 DIY filing that costs you £2,000 in overpaid tax is the more expensive option.
For the full decision framework — including a 5-question self-test to determine whether you need an accountant — see our should I hire an accountant guide.
How to Get the Best Price
- Organise your records before you ask for a quote. Clean, categorised records (ideally in accounting software) reduce the accountant’s time and often the fee.
- Get 2–3 quotes. Prices vary significantly between firms. Ask exactly what’s included — some quote a low fee that doesn’t include filing, amendments, or HMRC correspondence.
- Ask about fixed-fee pricing. Most modern accountants offer fixed fees rather than hourly rates. A fixed fee means you know the cost upfront and won’t get a surprise bill.
- Check if software is included. Some accountants include accounting software (like FreeAgent or Xero) in their monthly fee, which saves you £10–£40/month separately.
- Don’t overpay for a simple return. If your return is genuinely simple, a £150–£200 accountant or a £100–£150 online service is sufficient. A £500 traditional firm won’t find more reliefs on a one-source return with the trading allowance.
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