Self Assessment, start to finish
Registering you with HMRC, preparing your return and filing it on time. We reconcile it against your records and tell you exactly what to pay and when.
Who we helpIndustry guide
The sole trader accountant who keeps it simple.
Self Assessment, expenses and Making Tax Digital handled by a sole trader accountant, so you can get on with the work.
You went self-employed to run the show, not to wrestle with HMRC. As a specialist sole trader accountant, we take your Self Assessment, your expenses and your record-keeping off your hands. First year trading, side hustle going full-time, or weighing up a limited company? We know how self-employment actually works, claim every expense you are owed, and keep your tax bill as low as it legitimately can be. Book a call with an accountant for sole traders who picks up the phone, on one fixed monthly fee.
- 4.9 Google · 63 reviews
- ACCA-qualified
- 30-day money-back
The problem
Why a Generic Accountant Often Gets It Wrong
Plenty of accountants treat a sole trader like a shrunken company. They file last year, send a bill, and never tell you what could have cut your tax.
Missed expenses. The trading allowance ignored. National Insurance you did not understand. Payments on account that blindsided you. So you overpay, and you never quite know why.
A specialist sole trader accountant works the other way round. Because your business is you, we get to know how you actually earn, then we look for where the money leaks. We do not just record your numbers. We improve them.
Tailored services
What We Handle, So You Don't Have To
01 02 Expenses and the trading allowance
We claim use of home, mileage, tools and kit, and weigh the £1,000 trading allowance against your real costs to pick whichever leaves you better off.
03 National Insurance worked out
Class 2 and Class 4 National Insurance are widely misunderstood. We calculate them correctly and flag the voluntary route to protect your State Pension if profits are low.
04 Bookkeeping that fits your day
Simple mobile invoicing and receipt capture, so your records stay current without you living in a spreadsheet. Accurate books mean accurate tax.
05 VAT advice near the threshold
We watch your rolling turnover, warn you before you trip the £90,000 VAT threshold, and handle registration and returns if and when it makes sense.
06 When to think about a company
We tell you honestly whether staying a sole trader or incorporating puts more in your pocket, based on your actual profit, not a one-size-fits-all rule.
Self Assessment
Self Assessment and Payments on Account, Explained
When you go self-employed, you report your profit to HMRC through Self Assessment. You register, file a return each year, and pay the Income Tax and National Insurance due on your profit.
The part that catches people out is payments on account. Once your bill passes a certain size, HMRC asks you to pay next year in advance, in two instalments. Your first proper year can therefore feel like paying one and a half years of tax at once.
We prepare and file your return to the 31 January online deadline, reconcile it against your records, and tell you the exact figure to pay and when, payments on account included. No guessing, no January scramble.
Allowable expenses
What Can Sole Traders Actually Claim?
More than you think. Good accounting for sole traders starts with claiming every legitimate cost of doing business.
- Use of your home as an office
- Business mileage in your own vehicle
- Tools, equipment and software
- Stock, materials and supplies
- Phone, broadband and business insurance
- Accountancy and bank or card fees
- Training and trade subscriptions
- Marketing, website and advertising costs
On a vehicle you can claim actual running costs or simplified mileage at 55p a mile for the first 10,000 miles, then 25p. We work out which one wins. If your costs are tiny, the £1,000 trading allowance may beat claiming real expenses, and we check that too.
National Insurance
Class 2 and Class 4 National Insurance
Self-employed National Insurance comes in two flavours, and most sole traders are fuzzy on both.
Class 4 is charged as a percentage of your profits above a threshold, and it sits on top of your Income Tax in the same Self Assessment bill. Class 2 is a separate, flat weekly contribution that, importantly, builds your entitlement to the State Pension and certain benefits.
If your profits are low, paying Class 2 voluntarily can be one of the best-value decisions you make, protecting your pension record for a small sum. We work out exactly what applies to you and flag when the voluntary route is worth it.
Business structure
Sole Trader vs Limited Company
As a sole trader, life is simple. You and the business are one and the same, your admin is light, and you pay Income Tax and National Insurance on your profit through Self Assessment.
Earn more, and a limited company can often keep more in your pocket. You pay Corporation Tax on profit, then draw a small salary and dividends, which can be more efficient at higher levels of income.
But a company brings real admin: year-end accounts and a Confirmation Statement at Companies House, director responsibilities and tighter record-keeping. It is not automatically better, it is better at a certain level of profit.
The honest answer depends on your numbers. We model both and tell you which one genuinely leaves you better off, rather than pushing you into a company you do not need yet.
Day-to-day numbers
Bookkeeping and Making Tax Digital
Good books sound dull. Done right, they are the difference between guessing and knowing what you can afford to take out of the business.
We set up your bookkeeping with simple mobile invoicing and receipt capture, so you snap a photo at the job rather than hunting through a shoebox in January.
It also gets you ready for Making Tax Digital for Income Tax, which will require self-employed people over a certain income to keep digital records and send HMRC quarterly updates. Get your records digital now and the change is barely noticeable. Leave it, and it becomes a deadline-week scramble.
Simple, fixed fees
Fixed Monthly Pricing for Sole Traders
Most sole traders pay between £99 and £199 a month, depending on how much you need us to do.
No hourly rates. No surprise bills. One fixed fee, a named, qualified accountant for sole traders, and a 30-day money-back guarantee.
Essentials
Startups and small companies that need essential compliance and year-end support without VAT or payroll.
£99/month- Preparation of Company Year-End Financial Statements
- Year End Corporation Tax Computation
- Submission of CT600 to HMRC
- Statement of Account submissions to Companies House
Premium Plus
Growing businesses that need complete accounting services, VAT return management, and payroll handling.
£199/month- Everything in Essentials
- Quarterly VAT return calculation and submission
- Payroll and benefits management
Enterprise
Established businesses that want strategic mentoring, business planning, and a part-time finance director driving growth.
£499/month- Everything in Premium Plus
- Business mentoring
- Part-time finance director
- Business plan
Trusted by the self-employed
What Our Clients Say.
I’ve used several accountants in the past, but hands down there is no one better than Harvey at Zmartly. He really understands exactly what advice you’re looking for and explains everything clearly and professionally. Nothing ever feels rushed…
HeenaVerified Google review · 4 months agoI’ve had an excellent experience working with Zmartly. Harvey and the team are professional, responsive, and genuinely supportive. They explain things clearly, stay on top of deadlines, and always look for practical ways to save tax and improve…
land4 success (chill feel good)Verified Google review · 5 months agoI started working with Zmartly Accountants after having serious issues with my previous accounting firm. They were missing deadlines, incorrectly calculating VAT, constantly late, and extremely difficult and frustrating to communicate with. Switching to Zmartly was a huge…
Jorge Carballo GomezVerified Google review · 5 months agoGreat proactive service always up to date regarding accounting legislation. Harvey and Team will be always helping you with advise how to make your books look good. Already over 4 years using their service very happy.
Auris Property AcademyVerified Google review · 8 months agoI've had a terrible experience with multiple accountants. Zmartly have been incredible. If you do ecommerce / Amazon FBA you definitely need to go with someone who understands the complexities with it. Thanks to Harvey and his amazing…
Sean BarringtonVerified Google review · 5 months agoI’ve used several accountants in the past, but hands down there is no one better than Harvey at Zmartly. He really understands exactly what advice you’re looking for and explains everything clearly and professionally. Nothing ever feels rushed…
HeenaVerified Google review · 4 months agoI’ve had an excellent experience working with Zmartly. Harvey and the team are professional, responsive, and genuinely supportive. They explain things clearly, stay on top of deadlines, and always look for practical ways to save tax and improve…
land4 success (chill feel good)Verified Google review · 5 months agoI started working with Zmartly Accountants after having serious issues with my previous accounting firm. They were missing deadlines, incorrectly calculating VAT, constantly late, and extremely difficult and frustrating to communicate with. Switching to Zmartly was a huge…
Jorge Carballo GomezVerified Google review · 5 months agoGreat proactive service always up to date regarding accounting legislation. Harvey and Team will be always helping you with advise how to make your books look good. Already over 4 years using their service very happy.
Auris Property AcademyVerified Google review · 8 months agoI've had a terrible experience with multiple accountants. Zmartly have been incredible. If you do ecommerce / Amazon FBA you definitely need to go with someone who understands the complexities with it. Thanks to Harvey and his amazing…
Sean BarringtonVerified Google review · 5 months ago
4.9
Google · based on 63 reviewsCommon questions
Frequently Asked Questions
Register for Self Assessment by 5 October after the end of the tax year you started trading. The online filing and payment deadline is 31 January following the 5 April tax year-end, so your 2025/26 return is due by 31 January 2027. If your bill is over £1,000, you will also make payments on account on 31 January and 31 July. We track all of these for you.
You pay Class 4 National Insurance at 6% on annual profits between the lower limit (around £12,570) and £50,270, then 2% on profits above that. Class 2 is £3.65 a week for 2026/27. If your profits are low, paying Class 2 voluntarily can still protect your State Pension entitlement, we will advise whether that is worth it for you.
Allowable business expenses reduce your taxable profit: business mileage at 55p per mile for the first 10,000 miles (25p after), a use-of-home flat rate, stock, tools, software, professional fees and more. Alternatively, the £1,000 trading allowance covers everything if your costs are tiny. We compare methods and claim whichever leaves you better off.
VAT registration is compulsory once your taxable turnover passes £90,000 over any rolling 12-month period, or if you expect to exceed it in the next 30 days. Below that it is voluntary, and sometimes worthwhile, for example via the Flat Rate Scheme. We watch your turnover and tell you before you hit the threshold, so you never register late.
From 6 April 2026, sole traders with qualifying income over £50,000 must keep digital records and send HMRC quarterly updates through compatible software, plus a final year-end declaration. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028. We get you on Xero, QuickBooks, FreeAgent or Sage and handle the quarterly filings.
It depends on your profit level, how much you draw, and your appetite for admin. Incorporating can save tax once profits are higher, but it adds Corporation Tax (19% up to £50,000, rising to 25% over £250,000 with marginal relief), payroll and Companies House filings. We model both for your actual numbers before you decide, no one-size-fits-all answer.
Fixed monthly pricing of £99, £199 or £499 depending on the support you need, on rolling monthly terms with a 30-day money-back guarantee. You get a named, qualified accountant and replies within 72 hours. No hourly billing and no surprise invoices.
Guides for sole traders
Plain-English explainers, kept current with the latest HMRC rules.
Stop guessing. Stop overpaying. Let's sort your tax once and for all.
Zmartly Ltd · 20–22 Wenlock Road, London N1 7GU · 020 8175 5145 · info@zmartly.co.uk
ICAEW, ACCA and AAT qualified accountants.
Further reading