Sole trader accountant fees sit across a surprisingly wide range. Depending on who you ask, you might hear anything from around £30 a month for a bare-bones online service up to several hundred pounds a month for a more hands-on engagement. That spread isn't random — it reflects real differences in what's being included, the complexity of the work, and the level of advice on offer.

The short version is this: for most sole traders earning above roughly £30,000 a year, a competent accountant should save you more than they cost — through legitimate tax planning, avoided penalties, and time back in your week. The question isn't really whether you can afford an accountant; it's whether you can afford not to have one.

Below we set out the main factors that drive sole trader accountant fees in 2026, what you should expect to receive at different price points, and the signals that suggest your current arrangement — or absence of one — may be costing you money.

Before you compare quotes, it helps to understand what the variables are. Sole trader accounting is genuinely simpler than limited company work — there's no corporation tax, no Companies House filing, no directors' loan account to manage — but "simpler" doesn't mean trivial, and it certainly doesn't mean one-size-fits-all.

The key factors that move the fee up or down:

• Turnover and transaction volume. A sole trader turning over £40,000 with 200 invoices a year is a different proposition to one turning over £200,000 across multiple revenue streams. More transactions mean more bookkeeping time.
• VAT registration. Once you're VAT-registered — mandatory above £90,000 turnover, optional below — quarterly VAT returns add meaningful work. Making Tax Digital for VAT (MTD) requirements apply here too.
• Income complexity. Multiple income sources, rental income, overseas earnings, or capital gains all add complexity to a self-assessment return and, rightly, increase the fee.
• Bookkeeping. If you're handing over clean, reconciled cloud accounting data, the accountant's job is easier. If you're handing over a shoebox or a spreadsheet, the clean-up cost falls somewhere.
• Geography. London-based practices typically charge more — one estimate puts the premium at up to 25% above the national average — though cloud accounting has made location less determinative than it used to be.

Understanding these variables means you can assess a quote intelligently rather than just comparing headline numbers.

The published market data points to a fairly wide band. Online-only services aimed at sole traders with simple affairs start from around £25–£40 per month plus VAT — these typically cover self-assessment filing and not much else. Mid-market practices tend to come in at £50–£150 per month for a more complete package. At the more comprehensive end — where advisory input, management reporting, or VAT is included — monthly fees of £150–£350 are not unusual.

On an annual basis, that works out at somewhere between roughly £300 and £4,000 depending on scope. For comparison, Intuit's research into small business accounting costs suggested an average monthly fee across SMEs of around £360, though that population includes limited companies with more complex requirements.

One thing worth flagging: most published fees are quoted exclusive of VAT. A fee of £50 per month is £600 per year plus VAT — meaning the actual cash cost is £720. For a VAT-registered sole trader who can reclaim input VAT on professional fees, this reduces the net cost, but it's worth checking before you compare.

An annual-only arrangement — where the accountant files your self-assessment return once a year without any ongoing support — can come in at £150–£500 depending on complexity. That's the cheapest option, but it's also the model least likely to surface tax planning opportunities during the year when they can actually be acted on.

This is where a lot of sole traders get caught out. A low headline fee is only good value if it covers what you actually need. Before agreeing a quote, it's worth confirming exactly what's in scope.

At a minimum

• Preparation and filing of your annual self-assessment tax return
• Calculation of your income tax and National Insurance liability
• Basic advice on allowable expenses

What a more complete engagement should add

• Ongoing bookkeeping support or review of your cloud accounting records
• Quarterly VAT returns (if applicable)
• Proactive tax planning during the year — not just at year end
• Access to the accountant for ad hoc questions without a separate charge every time
• Making Tax Digital compliance support

In our experience, the sole traders who get the most value from their accountant are the ones who treat the relationship as ongoing rather than once-a-year. A tax return filed in January tells you what you owe; a conversation in October tells you what you can still do about it.

If you're unsure whether your current accountant is covering the basics, our guide on whether you need an accountant as a sole trader sets out the core services to look for.

There's a point at which debating the cost of an accountant becomes academic. We'd broadly put that at annual turnover of around £30,000 or above — at which point the income tax and National Insurance liability is large enough that even modest tax planning will typically outweigh the accountant's fee.

Beyond turnover, here are the situations where the maths tends to be most compelling:

• You're VAT-registered. The admin burden of quarterly MTD-compliant returns, combined with the risk of errors and penalties, makes professional support a straightforward call.
• You have multiple income streams. Employment income plus self-employment, rental income, or dividends from a company — the interactions between these can produce unexpected tax bills if not managed.
• You're spending significant time on your own books. If you're doing two or more hours of bookkeeping admin each month, you're effectively paying yourself below minimum wage to do work a professional would handle in a fraction of the time, more accurately, and with software that gives you a real-time picture of your finances.
• You're growing. A sole trader approaching the VAT threshold or considering incorporation needs strategic input, not just compliance. The cost of getting the timing wrong can significantly exceed a year's worth of accountancy fees.

One client described it to us plainly: the money saved more than covers the fees. That's a common experience once you're working with someone who's genuinely engaged with your situation.

Most modern accountancy practices — including us — work on fixed monthly fees rather than billing by the hour. There are good reasons for this beyond commercial preference.

Hourly billing creates a perverse incentive: the client worries about calling or emailing because every question is a potential charge. That leads to situations where tax-saving opportunities are missed simply because the sole trader didn't want to "bother" the accountant. A fixed monthly fee removes that friction. You know what you're paying, and you're incentivised to actually use the relationship.

Hourly rates for accountancy work in the UK typically run from around £25 at the entry level to £100 or more for senior-level advisory work. For a sole trader who needs occasional help with a straightforward self-assessment, ad hoc hourly billing might make sense. For anyone with regular bookkeeping, quarterly VAT returns, or who wants ongoing access to advice, a fixed-fee arrangement will almost always work out better value.

When you're comparing quotes, ask what the fixed fee covers and what triggers an additional charge. A low monthly retainer with a long list of extras can end up more expensive than a slightly higher all-inclusive fee.

You can also explore how sole trader accountant cost breaks down by service for a more detailed look at what different engagement models typically include.