If you’ve been searching for how much an accountant costs for a sole trader, you’ve probably found a fairly wide range — anywhere from £30 a month to several hundred. The spread is real, and it reflects genuine differences in what’s included, how complex your affairs are, and whether you’re dealing with a one-person practice or a regional firm with a reception team and overheads to match.

The short answer is: for most straightforward sole traders, you should expect to pay somewhere between £50 and £150 per month for ongoing support, or £150 to £400 per year if you only need someone to handle your Self Assessment. But the number that matters is the one scoped to your actual situation — not the industry average. Below, we walk through what drives the cost in each direction, and how to judge whether a quote is reasonable.

Before you can answer the cost question, it’s worth being clear on what service you’re actually after. A sole trader’s accounting needs generally fall into one of two buckets:

• Self Assessment only — you keep your own records through the year, and you want an accountant to prepare and file your tax return. This is the minimum.
• Ongoing support — bookkeeping kept in order, VAT returns filed if you’re registered, records maintained in something like Xero, plus the year-end Self Assessment. This is the fuller picture.

Most sole traders starting out only want the first option. As turnover grows — particularly once you’re approaching or past the VAT threshold (£90,000 for 2025/26) — the ongoing package starts to make a lot more sense, because the time you’d spend doing it yourself is worth more than the fee.

There’s also a middle ground: some clients handle their own day-to-day bookkeeping in Xero and just bring an accountant in for the year-end review and Self Assessment filing. That’s a reasonable approach if you’re organised and your affairs aren’t complex.

Here’s how the numbers broadly break down for UK sole traders this year:

Self Assessment only (one-off annual fee)

For a straightforward sole trader with one income source and clean records, expect to pay in the region of £150 to £400 per year. If your return involves multiple income streams, property, capital gains, or employment income alongside self-employment, that figure will sit at the higher end or above it.

Monthly all-inclusive package

A monthly package covering bookkeeping, VAT returns (if applicable), and Self Assessment typically runs from £60 to £150 per month for a simple sole trader. More complex arrangements — higher transaction volumes, CIS deductions, VAT, or additional income sources — push that higher. If someone is quoting you under £50 a month for a genuinely full service, it’s worth asking what’s actually included.

Hourly rates

Some accountants still bill by the hour. Smaller practices typically charge £50 to £150 per hour; senior advisers at larger firms charge more. For most sole traders, hourly billing is unpredictable — fixed fees are easier to budget for and tend to feel fairer when the work is routine.

A note on what we’ve seen in online discussions: a fee of around £140 per month being flagged as high for a lower-turnover sole trader is a fair benchmark. If you’re early-stage with simple books, you shouldn’t be paying that.

The factors that move the number the most, in our experience:

• Turnover and transaction volume — more income and more transactions mean more work. A sole trader turning over £30,000 with 20 transactions a month is a very different job to one turning over £200,000 with daily purchases and sales.
• Whether you’re VAT registered — quarterly VAT returns under Making Tax Digital add meaningful work to the year. If you’re on the flat rate scheme it’s lighter; standard-rated with complex apportionment is heavier.
• How clean your records are — if you hand over a year’s worth of unreconciled bank statements in January, expect a higher fee. If your Xero is tidy and up to date, the accountant has less to do.
• CIS deductions — if you’re a subcontractor in construction, your return involves verifying deductions and reclaiming overpaid tax, which takes additional time.
• Multiple income sources — rental income, dividends from a limited company, capital disposals — each one adds complexity.

None of this is hidden. A good accountant should be able to explain exactly what they’re pricing and why — and the quote should be in writing before any work starts.

We work on fixed fees at JD Accountancy, and we think that’s the right model for most sole traders. Here’s why.

If you pay by the hour, every question you ask your accountant has an implicit cost attached to it. Most clients are aware of this, even if they don’t say it — and the result is they don’t ask the question, or they ask it six months too late. That’s bad for them and it’s a poor outcome professionally.

A fixed monthly fee changes that dynamic. You know what you’re paying. You can message, call, or WhatsApp with a quick question without worrying about a bill landing at the end of the month. That access is genuinely useful — particularly for sole traders who are making decisions on their own and just need someone to sanity-check something occasionally.

The caveat is that fixed fees need to be scoped properly at the outset. If an accountant quotes you a low fixed fee and then adds extras every time something comes up, it’s not really fixed. Make sure the engagement letter is clear on what’s included and what falls outside it.

From a practical standpoint, a fixed fee also makes it easier to compare quotes. When you’re looking at two firms, you can put the numbers side by side — provided you’re comparing the same scope.