A straightforward Self Assessment return should not cost hundreds of pounds. Plenty of firms charge that anyway — usually because they bill by the hour and a simple return still gets a partner’s time on the clock.
Here is what the market actually charges in 2026, what drives the number up, and where the genuine free routes still exist.
The free route still exists — with one large caveat
HMRC’s online Self Assessment service is free. If your affairs are simple — one source of income, no property, no gains, no foreign income — you can file yourself in an evening and pay nothing.
The caveat is Making Tax Digital. MTD for Income Tax went live on 6 April 2026 for sole traders and landlords with qualifying income over £50,000, measured on their 2024/25 return. If you are in that group you must keep digital records and submit quarterly updates using MTD-compatible software, which is not free. The threshold drops to over £30,000 from April 2027 and over £20,000 from April 2028, so the free DIY route narrows every year.
There is one legitimate way to reduce that cost: FreeAgent is free for NatWest, Royal Bank of Scotland, Ulster Bank and Mettle business account holders. Its sole trader plan lists at £19 a month ex VAT, so that is a real saving if you already bank with one of them or are willing to move.
What the market charges
Prices below were checked against provider pricing pages on 20 August 2026, with Mazuma re-verified on 21 August 2026. UK providers usually quote plus VAT, and every monthly subscription below is on that basis. Watch for providers that switch bases between pages — Mazuma quotes its monthly subscriptions plus VAT but its one-off accounts packages inclusive of VAT.
Self-file software
| Provider | Price |
|---|---|
| Taxpipe | £59 per return (does not file at Companies House) |
| TinyTax | £59 per year |
| Xero | From £7 a month ex VAT (Simple); £18 for Ignite from 1 September 2026 |
| FreeAgent | £19 a month ex VAT for sole traders — free for NatWest, RBS, Ulster Bank and Mettle business account holders |
QuickBooks also offers low-cost entry tiers; check the current price on their site before budgeting, as it moves.
Monthly accountancy subscriptions (ex VAT)
| Provider | Entry price |
|---|---|
| Mazuma | From £38 + VAT a month |
| Taxfix | From £39 + VAT a month |
| The Accountancy Partnership | From £39.50 + VAT a month (£474 a year) |
| Sleek Basic | From £50 + VAT a month |
| Osome Operate | From £850 + VAT a year, billed annually (about £71 + VAT a month equivalent) |
| Gorilla | £125 + VAT a month, flat (£1,500 a year) |
| Osome Grow | From £137 + VAT a month (£1,644 a year) |
Osome Operate is sold as an annual plan, so the annual figure is the one you pay. The monthly equivalent is indicative only — £71 × 12 does not reconcile to £850 because the annual billing carries a discount.
A note on Taxfix: it was formerly TaxScouts, and taxscouts.com URLs now return 404. If you have an old bookmark or an old comparison article, it is out of date. Every Taxfix figure in this article is quoted plus VAT — £39 a month is the entry subscription, and its limited company packages are priced annually at £329 and £419, covered below.
Subscription tiers vary enormously in what they include. Read the inclusion list before comparing the headline numbers — a £39 tier and a £137 tier are rarely doing the same job.
What drives the price up
Every provider prices off broadly the same variables:
- Turnover band. The single biggest driver at the lower end.
- Monthly transaction volume. Fifty transactions a month is a different job from five hundred.
- VAT registration. This one is stark: Taxfix charges £329 + VAT for a non-VAT-registered limited company and £419 + VAT for a VAT-registered one under £200,000 turnover — a 27% jump for the registration alone.
- Number of directors and payroll headcount.
- Structural complexity. Multi-currency, alphabet share classes, corporate shareholders, property portfolios and e-commerce platforms all add work.
- Backlog. This is the one that surprises people. Osome charges £850 a year for historical work; Sleek charges £750 per financial year backdated. If you are three years behind, you are paying three times.
Where the four-figure quotes come from
Traditional high-street firms price on time. A partner or manager reviews the file, an assistant does the input, and both are on the clock. That model made sense when returns arrived in a carrier bag. It makes considerably less sense when the underlying records are already in Xero.
The result is that essentially identical work is quoted anywhere from £150 to well over £1,000 depending on who you ask — and the difference is often the firm’s overhead structure, not the complexity of your affairs. Hourly billing also means the number you are quoted is not the number you pay.
What a Self Assessment fee should include
Before comparing prices, check what is actually inside the fee. A complete service should cover:
- Preparation of the return from your records
- All relevant supplementary pages — self-employment, property, capital gains, foreign income, partnership
- Review and sign-off by a qualified accountant
- Submission to HMRC and confirmation of receipt
- A clear statement of what you owe and when
Things that are commonly charged extra and worth asking about up front: supplementary pages beyond the basic return, capital gains computations, prior-year amendments, catch-up work on late years, and correspondence with HMRC if a query arises.
Check the regulation, not just the price. “Accountant” is not a protected term in the UK. Anyone can use it. ICAEW-regulated firms are subject to professional standards, continuing education requirements, mandatory professional indemnity insurance and a complaints process. That is not a guarantee of a particular outcome with HMRC — nobody can offer that — but it is a meaningful difference in accountability.
How to actually decide
Three questions settle it for most people.
Are you inside MTD for Income Tax? If yes, you need compatible software and four quarterly submissions plus a year-end return. That is a materially bigger job than one annual return, and the DIY calculation changes.
How complex is the return? One trade, one bank account and no assets — file it yourself. Property, gains, foreign income or a partnership share — the cost of getting it wrong exceeds the fee.
How much is your time worth? A first Self Assessment realistically takes an unfamiliar person several hours across the year, and the outcome is a return nobody has checked.
Frequently asked questions
How much does an accountant charge for a Self Assessment tax return?
The market ranges widely. Self-file software starts around £59 per return, monthly accountancy subscriptions start from roughly £38 to £50 a month depending on whether the quote includes VAT, and traditional high-street firms billing by the hour can reach four figures for the same work.
Can I file my Self Assessment tax return for free?
Yes, through HMRC’s online service, if you are not mandated into Making Tax Digital for Income Tax. If you are — currently sole traders and landlords with qualifying income over £50,000 — you must use MTD-compatible software, which is not free.
Why do Self Assessment fees vary so much?
Turnover, transaction volume, VAT registration, complexity and backlog all move the price. Pricing model matters too: fixed-fee providers quote the job, while hourly firms quote an estimate that can move.
Is there a cheap way to get MTD-compatible software?
FreeAgent is free for NatWest, Royal Bank of Scotland, Ulster Bank and Mettle business account holders. Its sole trader plan is £19 a month ex VAT — the £33 figure quoted elsewhere is the limited company tier.
What should be included in a Self Assessment filing fee?
Preparation from your records, all relevant supplementary pages, review by a qualified accountant, submission to HMRC, and a clear statement of what you owe and when. Ask specifically about supplementary pages, capital gains computations and catch-up work, which are commonly charged extra.
A fixed fee, quoted up front
SmartFiling files Self Assessment and MTD for Income Tax returns for a fixed fee — quoted before the work starts, with no hourly billing and no surprise invoices. Turnaround is three weeks from receiving your records, and every return is reviewed and signed off by an ICAEW Chartered Accountant.
SmartFiling is the trading name of Ballards Newman (Finchley) Limited, an ICAEW-regulated London chartered accountancy practice with roots in the 1970s and more than 500 clients. Everything is handled online. No appointments, no phone calls required.
