For a sole trader, an accountant does five things: keeps your business records in a state HMRC would accept and you can actually use, prepares and files your Self Assessment tax return, calculates your tax with every expense and allowance you are entitled to claimed, deals with VAT if your turnover reaches it, and gives you a planning view, from saving for tax bills to knowing when incorporation would start paying. Sole trader affairs are simpler than a company’s, which cuts both ways: the work costs less, and owners more often assume they can skip it entirely. Whether that assumption holds depends on how much your time is worth and how confident you are that your return claims everything it should.
Keeping the records right
You and the business are legally the same person, but the records still have to separate business from personal. GOV.UK’s guidance for the self-employed sets out what you must keep (income, expenses, and the evidence behind both) and for how long.
An accountant either does this bookkeeping for you or sets you up to do it well: a separate business bank account, digital records, expenses captured as they happen rather than reconstructed in January. This groundwork matters more than it looks, because record-keeping for the self-employed is moving progressively onto a digital, more frequent footing under Making Tax Digital. Sole traders whose habits are already digital will barely notice the transition; those still on carrier bags of receipts will.
The Self Assessment return
The centre of a sole trader’s tax year is the Self Assessment return, covering your business profits alongside any other income: employment, property, savings, whatever applies. GOV.UK explains the system; the accountant’s job is producing a return that is accurate, complete and filed on time, from records they have checked rather than figures they have accepted.
Accuracy runs in both directions. An accountant makes sure nothing taxable is missed (the errors that cause trouble) and equally that nothing claimable is missed, which is the part that pays for the service. What to hand over is listed in what an accountant needs for Self Assessment.
Calculating the tax and claiming everything you are entitled to
Self-employed tax is not just a rate applied to profit. There are allowable expenses with genuinely fuzzy edges (use of home, vehicle costs, items used partly for business), plus capital allowances on equipment, and National Insurance alongside income tax. Then there is the payment mechanism: Self Assessment collects tax in instalments that include payments on account towards the following year, a system that routinely ambushes people in their early years with a bill half as large again as expected.
An accountant gets the claims right at the defensible maximum, calculates what is actually due and when, and tells you the numbers early enough to save for them. Current rates, thresholds and deadlines are on GOV.UK. For many sole traders, being told in autumn what January will cost is by itself worth the fee.
VAT, when turnover gets there
Sole traders register for VAT on exactly the same tests as companies. The obligation follows turnover, not structure, and the rolling nature of the turnover test catches people whose good year sneaks past the threshold. An accountant watches the position, handles registration at the right moment and takes on the quarterly cycle; the details are in how an accountant can help with VAT.
Planning: the questions beyond this year’s return
The recurring planning question for a successful sole trader is structure: at what point would a limited company serve you better? The answer moves with your profits, your plans and the tax rules, so it deserves revisiting rather than a one-time verdict. An accountant runs the comparison with your actual numbers and, just as importantly, is candid when the answer is “stay as you are”, since incorporation brings obligations as well as opportunities.
Alongside that sit the ordinary planning threads: timing equipment purchases, pension contributions, handling a growing or shrinking year, and preparing for the shift to digital quarterly reporting. All of it is the sole trader slice of the full role described in what an accountant does for a small business.
Frequently asked questions
Do sole traders really need an accountant?
Need, no: the system is designed to be self-serviceable. The practical question is whether the fee is smaller than the value of your time, the claims you would miss and the errors you would make. For very simple affairs, honest accountants say DIY is fine. Complexity, growth or a hatred of paperwork changes the answer.
What does a sole trader accountant cost compared with a company accountant?
Less, generally, because the compliance load is lighter: no statutory accounts, no Companies House. The structure of fees and what drives them is its own topic; the short version is that tidy records make everything cheaper.
Can an accountant help me register as self-employed?
Yes. Registration is straightforward (GOV.UK’s page on setting up as a sole trader covers it), but an accountant will make sure it happens at the right time and that record-keeping starts properly from day one, which is where new sole traders usually stumble.
What about my other income, such as employment, rental or savings?
It all belongs on the same Self Assessment return, and it interacts: other income affects the tax on your profits and vice versa. An accountant prepares the return as a whole, which is where several of the commonly missed claims and charges live.
When in the year should I hand over my records?
As soon as your tax year’s records are complete. Early preparation means you know the bill months before it is due, and you can file early and still pay at the deadline. Nothing about waiting until January improves any part of the process.
How we can help
Our Self Assessment service covers the return, the tax calculation and the planning around it. See also our page for sole trader clients. Request a quote and get January sorted in advance.