How Much Does a Self Assessment Accountant Cost in the UK?

What drives the price

The number of income sources, rental properties, capital gains, foreign income and whether bookkeeping is included all affect the fee. A single rental property with a mortgage, for example, takes more work than a sole trader with one income stream, because interest restrictions and allowable costs need checking.

Fixed fee or hourly

A fixed fee gives certainty. Hourly rates can be cheaper for very simple returns but may grow if records are incomplete. Before agreeing an hourly rate, ask for an estimate of the hours and a cap.

What should be included

Preparing the return, calculating tax, filing with HMRC, a copy of your calculation and answering simple HMRC queries. Check whether payments on account are calculated for you and whether advice during the year costs extra.

Hidden extras to check

Fees for late records, extra income types, amendments and responding to HMRC enquiries. Ask for these in writing — a cheap quote can double once extras are added.

Reading a quote properly

Two accountants can quote very different prices for what looks like the same job, so the first step is to compare like with like. A fee for a straightforward sole trader return with a single income source is not the same as a fee for someone with employment income, rental properties, share sales and foreign interest. Ask what the quote covers: preparing the return, filing it online, calculating payments on account, answering questions after filing and dealing with simple HMRC letters. Also ask whether the price is fixed or can increase, whether VAT is added, and what happens if you send records late or in a poor state.

Our own prices start at a fixed fee from £199 + VAT, and you will know the amount before you commit. The final fee depends on the complexity of your tax affairs, so the sensible approach with any accountant is to describe your circumstances honestly and ask for a written quote. For a deeper comparison of pricing models, read fixed fee versus hourly accountants.

Worked example: fixed fee or hourly?

This is an illustrative comparison using assumed figures, not a statement of what any firm charges. Suppose a sole trader has a simple return.

The fixed fee gives certainty, while the hourly bill depends on how long the work takes. Hourly pricing is not automatically worse, but you need to know the likely hours in advance.

Does the fee pay for itself?

Imagine the same sole trader would have missed £1,500 of allowable expenses, such as a proportion of home office costs and a work phone. At a combined 26% marginal rate (20% income tax plus 6% Class 4 National Insurance) that is worth £1,500 x 26% = £390 in tax. Add avoiding a £100 late filing penalty and the saving comfortably exceeds a £238.80 fee. Not every case works out this way, and a very simple return may not produce savings, but it shows why the right comparison is the fee against the tax and penalties at stake.

What affects the price

• The number of income sources, such as self-employment, property, dividends and capital gains.
• The quality of your records and bookkeeping.
• Whether you need help registering with HMRC or catching up on previous years.
• Making Tax Digital for Income Tax, which applies from 6 April 2026 if qualifying income is over £50,000, and from April 2027 and April 2028 at lower thresholds.
• Whether the service includes ongoing advice or only a once-a-year return.

Common mistakes

• Choosing the cheapest quote without checking what is included.
• Failing to ask whether VAT is added.
• Hiring someone who cannot show they are suitably qualified or regulated.
• Sending records at the last minute and paying a premium for urgent work.
• Paying nothing for advice and then paying more in penalties and missed reliefs.

Practical checklist

1. List your income sources before asking for quotes.
2. Ask for a written, itemised quote including VAT.
3. Check the accountant’s qualifications and who will actually prepare your return.
4. Confirm the filing deadline they will work to, such as 31 January for online returns.
5. Read our list of questions to ask before hiring an accountant.

You may also like how an accountant can save you tax and DIY versus using an accountant.

How SATR can help

Our qualified UK accountants prepare and file your return online for a fixed fee from £199 + VAT, so there are no hourly surprises. You can see what is involved on our sole trader service page or start straight away through our order page.

This article is general information, not personal tax advice.

Getting more value from the fee you pay

The cost of an accountant is partly in your hands. A well-organised client who sends clear records, answers questions promptly and files early is cheaper to work with than one who needs several rounds of chasing. Before you send anything, separate business and personal bank transactions, keep invoices and receipts together, and write a short note of anything unusual, such as buying a van, starting to rent out a property or selling shares. If you are new to self-employment, our first-year self-employed tax guide explains which records matter most. Good preparation reduces the risk of errors, shortens the time needed for your return and often leads to better claims for the costs you have really incurred.

Finally, remember that the fee is only part of the cost of getting Self Assessment wrong. Late filing carries a £100 penalty from day one, and unpaid tax attracts penalties and interest. Spending a known amount on getting it right is usually easier to manage than an unpredictable bill later.

Frequently asked questions

Is an accountant worth the money?

Often yes, because correct claims and avoided penalties can exceed the fee. For a basic-rate sole trader, finding just £1,000 of missed expenses saves £260 in tax and National Insurance at 26% — already more than a £238.80 fixed fee including VAT.

Can I pay online up front?

With SATR you order and pay online first, so you know the cost before work begins. VAT is shown separately at checkout.

Does the price change if I file late?

Fees are set by each accountant, so ask in advance. Our fixed-fee quotes are given upfront, but late filing itself can cost you a £100 penalty from HMRC on day one, so earlier is better.

Is the accountant fee tax deductible?

For a self-employed person, accountancy fees relating to the business are generally an allowable expense. Fees for personal tax matters may not be, so ask your accountant how it should be treated.

Should I choose an accountant for price alone?

Price matters, but scope, qualifications and service matter too. Compare what each quote includes, not just the headline figure. A £150 quote that excludes filing and VAT is not cheaper than a £199 + VAT fixed fee that includes everything.

The Bottom Line

A Self Assessment accountant typically costs from around £150 to £500 for a standard return, with rental, director or multi-income complexity pushing it higher. Compare written quotes like-for-like, confirm VAT and what is included, and weigh the fee against the tax, interest and penalties at stake.

If you want the cost settled upfront, SATR prepares and files your Self Assessment for a fixed fee from £199 + VAT — done online by qualified UK accountants. Order online now or see our Self Assessment pricing.