If you have searched for how much an accountant costs for a sole trader, you have probably already encountered a frustrating spread of numbers. Some sources quote a couple of hundred pounds a year; others suggest well over a thousand. Both figures can be correct — the problem is that they are describing completely different services.

In our experience working with sole traders across Hampshire and beyond, the fee question is almost always the wrong starting point. The better question is: what do you actually need from your accountant, and what would poor advice or missed tax planning cost you? Once you frame it that way, the numbers start to make more sense. This post walks through typical fees in 2026, the factors that move them up or down, and how to judge whether you are getting fair value for what you pay.

Before comparing prices, it helps to be clear on what is in scope. Sole trader accounting is not a single product — it is a range of services that can be bundled together or purchased individually, and the scope varies significantly depending on how your business operates.

At the minimum end, an accountant will prepare and file your Self Assessment tax return (SA100) once a year. This covers your income from self-employment, calculates the tax you owe, accounts for allowable expenses, and submits everything to HMRC by the January deadline. For a sole trader with straightforward finances and tidy records, this is the baseline.

Beyond that, you might need quarterly bookkeeping and reconciliation, VAT return preparation if you are VAT-registered, payroll if you have staff, and ongoing tax planning throughout the year. Some sole traders also want management accounts or regular check-ins to understand how their business is performing.

The reason fees vary so widely is that one firm might quote for the tax return alone while another is pricing an all-in service. When you see a headline fee, always check what it actually includes before drawing any comparisons.

With that context in mind, here are the fee ranges we see most frequently across the market in 2026.

Self Assessment only

A straightforward self-assessment return for a sole trader with modest income and reasonably organised records typically costs between £200 and £400 plus VAT. If your finances are more complex — multiple income sources, property income, capital gains, or messy records that need sorting first — that figure can move higher. Anything significantly below £200 is usually either a cut-price online portal with very little human input or a loss leader designed to upsell you later.

Monthly retainer packages

If you want bookkeeping, quarterly reviews, VAT, and your Self Assessment all handled on an ongoing basis, a monthly package is more appropriate. These range from around £75 to £250 per month for most sole traders, depending on turnover, transaction volume, and whether VAT is involved. That works out to £900–£3,000 per year, which sounds like more than a one-off return fee — but you are paying for year-round support, not a once-a-year filing exercise.

Making Tax Digital for Income Tax is also pushing more sole traders towards this model. When quarterly reporting becomes mandatory for you, a monthly retainer will likely make more financial sense than a series of one-off fees.

There is a meaningful difference between an accountant who files your tax return accurately and one who actually looks at your numbers and flags something useful. Both will complete the paperwork. Only one will tell you that you have been claiming expenses incorrectly for three years, or that a simple change to how you structure your income could reduce your tax bill going forward.

We have seen plenty of sole traders come to us after years with a cheap online service. The returns were filed on time — no complaints there — but nobody had ever reviewed their expenses properly, flagged a missed allowance, or suggested they think about their position ahead of a threshold change. The annual saving on accounting fees had, in several cases, cost them considerably more in tax they did not need to pay.

That is not an argument that you should pay the highest fee you can find. It is an argument that price and value are genuinely different things, and that the gap between a £150 return and a £350 return often comes down to whether a qualified human has actually looked at your situation or whether a system has just processed your numbers.

The questions worth asking any prospective accountant: will you review my expenses and flag anything I have missed? Do you offer proactive advice, or do you only respond to questions I raise? How do you handle things if my circumstances change during the year?

A few specific things consistently affect what sole traders pay, and it is worth understanding them before you approach a firm for a quote.

Turnover and transaction volume. Higher turnover and more transactions mean more bookkeeping work. A sole trader turning over £30,000 a year with a handful of invoices each month is a very different engagement from one turning over £150,000 with weekly sales, supplier payments, and mileage claims to reconcile.

VAT registration. Once you are VAT-registered, your accounting workload increases. Quarterly VAT returns, Making Tax Digital submissions, and the need to reconcile your VAT position add time — and therefore cost.

Record quality. If you hand over a shoebox of receipts in January, expect to pay more than someone who uses cloud accounting software and keeps records tidy throughout the year. Using Xero or QuickBooks properly throughout the year often reduces your accounting bill meaningfully at year end.

Location. London-based firms tend to charge more than regional practices, though cloud accounting has reduced this gap considerably. A Hampshire-based firm working remotely can offer the same quality of service as a London firm at a more competitive price — and in our experience, the quality of advice has nothing to do with the postcode.