Self Assessment for online sellers, worked from reconciled books.
Your Self Assessment return prepared from books that already match every payout, with your sales, fees, advertising and stock costs in the right places. You approve it, then we file it with HMRC. Part of every plan, from £89 a month.
- Online return due 31 January 2027
- Amazon, eBay, Etsy, Shopify, TikTok Shop
- In every plan, from £89 a month
In short
If you buy or make goods to sell for profit, you are probably trading. Once your gross trading income is over £1,000 in a tax year, you register for Self Assessment by 5 October after that year. For 2025 to 2026, a paper return is due by 31 October 2026, and an online return and the tax by 31 January 2027.
Selling your own things is different from running a shop.
GOV.UK says you are probably trading if you sell goods you bought to sell for profit, or goods you made, including hobby items. Selling your own personal possessions is usually not trading, though an item sold for more than £6,000 may mean Capital Gains Tax.
- Gross trading income of £1,000 or less a year: usually no need to tell HMRC
- Over £1,000: register for Self Assessment by 5 October after the tax year
- Claim the £1,000 allowance and you cannot deduct your actual expenses as well
If your real expenses are more than £1,000, claiming them instead of the allowance gives a lower taxable profit.
Five dates for the 2025 to 2026 tax year.
| What | Date |
|---|---|
| Register for Self Assessment, if this is your first return | 5 October 2026 |
| Paper return | 31 October 2026 |
| Online return | 31 January 2027 |
| Pay the tax for 2025 to 2026 | 31 January 2027 |
| Second payment on account towards 2026 to 2027 | 31 July 2027 |
From gross sales to trading profit.
Your return starts from the profit in your books. Here is how a year of payouts becomes that profit, with Class 4 National Insurance at the 2025 to 2026 rates (unchanged for 2026 to 2027): 6% on profits between £12,570 and £50,270, and 2% above.
| Line | Amount |
|---|---|
| Gross salesall channels, before fees | £62,000.00 |
| Refunds | −£1,900.00 |
| Marketplace and payment fees | −£9,300.00 |
| Cost of goods soldstock sold in the year | −£18,400.00 |
| Advertising | −£2,400.00 |
| Trading profit | £30,000.00 |
| Class 4 National Insurance6% of £17,430 (profit over £12,570), 2025 to 2026 rates | £1,045.80 |
Sample · demo seller, not a client · NI rates from GOV.UK · profit added up from the rows above · Income Tax not shown
HMRC already sees what the platforms report.
Since 1 January 2024, platforms report sellers' details and income to HMRC, and give each seller a copy of what they sent. Platforms report by calendar year, and your return covers the tax year from 6 April to 5 April, so we work out your income for the tax year from your own records and tie it back to the platform figures.
A platform report does not automatically mean you owe tax. It means your return should explain the same sales. How platform reporting works.
Late returns cost more the longer they wait.
| How late | Penalty |
|---|---|
| 1 day | £100 |
| 3 months | £10 a day, up to £900 |
| 6 months | 5% of the tax due or £300, whichever is greater |
| 12 months | Another 5% of the tax due or £300, whichever is greater |
Paying late adds 5% of the unpaid tax at 30 days, 6 months and 12 months, plus interest. Behind on your books? We catch up past months at £99 per month of records, then prepare the return.
What we keep for you, and for how long.
- All sales and income, from each platform's payout reports
- All business expenses, including receipts for goods and stock
- VAT records, if you are registered
- Bank statements for the business
- Your other personal income, for the return
GOV.UK asks sole traders to keep records for at least 5 years after the 31 January submission deadline. From 2024 to 2025, the cash basis is the default for sole traders; with traditional accounting, the value of stock at the end of the period is part of your records.
Self Assessment is part of every plan.
VAT-registered? Growth at £179 a month adds your quarterly VAT returns. On MTD for Income Tax? Your quarterly updates are included in every plan.
Your Self Assessment, with your monthly books
- Monthly bookkeeping with payout reconciliation
- Your Self Assessment return, prepared from those books
- Class 4 National Insurance and your payments on account worked out
- A second-person check, then your approval before we file
Prices in pounds sterling (GBP). The UK VAT treatment of our fees is shown on your invoice.
Just need one job done?
Keep your own books? We prepare your Self Assessment from your records and seller reports, and you approve it before we file. Want your books kept too? Starter at £89 a month includes both.
Self Assessment only
- Your SA100 tax return, with the self-employment pages: SA103S, or SA103F if your turnover was above the VAT threshold
- Your figures checked against your marketplace payout reports
- Class 4 National Insurance and your payments on account worked out
- Your approval, then we file it with HMRC
Prices in pounds sterling (GBP). The UK VAT treatment of our fees is shown on your invoice.
Self Assessment questions from online sellers.
Answered from the GOV.UK pages listed under Sources, with the date we read them.
Do I need to file if I only sell a little online?
If your gross trading income is £1,000 or less in a tax year, you usually do not need to tell HMRC. Over £1,000, you register for Self Assessment by 5 October after the tax year.
Is selling my old things on eBay or Vinted trading?
Usually not. GOV.UK says you probably do not pay Income Tax on selling your own personal possessions. Buying goods to resell for profit, or making goods to sell, is probably trading.
When is my 2025 to 2026 return due?
A paper return by 31 October 2026; an online return by 31 January 2027. The tax is due by 31 January 2027 too.
What National Insurance do I pay as a seller?
For 2026 to 2027, Class 4 is 6% on profits between £12,570 and £50,270 and 2% above. At profits of £7,105 or more, Class 2 is treated as paid.
The platform's figures don't match my return. Is that a problem?
Platforms report by calendar year, and your return covers 6 April to 5 April, so the numbers differ. We reconcile the two from your payout reports so the difference is explained.
What does it cost?
Self Assessment is included in every plan, from £89 a month with monthly bookkeeping. Catching up past months is £99 per month of records.
Sources
- GOV.UK: Expanding the cash basis for self-employed individuals and partnerships · read 17 Oct 2026
- GOV.UK: Check if you need to tell HMRC about income from online platforms · read 17 Oct 2026
- GOV.UK: Tax-free allowances on property and trading income · read 17 Oct 2026
- GOV.UK: Set up as a sole trader · read 17 Oct 2026
- GOV.UK: Check how to register for Self Assessment · read 17 Oct 2026
- GOV.UK: Self Assessment tax returns — Deadlines · read 17 Oct 2026
- GOV.UK: Self Assessment tax returns — Penalties · read 17 Oct 2026
- GOV.UK: Self-employed National Insurance rates · read 17 Oct 2026
- GOV.UK: Selling goods or services on a digital platform · read 17 Oct 2026
- GOV.UK: Business records if you're self-employed — What records to keep · read 17 Oct 2026
- GOV.UK: Business records if you're self-employed — How long to keep your records · read 17 Oct 2026
- GOV.UK: Cash basis · read 17 Oct 2026
- GOV.UK: Self Assessment: self-employment (short) (SA103S) · read 24 Oct 2026
- GOV.UK: Self Assessment: Self-employment (full) (SA103F) · read 24 Oct 2026
Tell us where you sell. You'll get a plan and a price in writing.
A 20-minute call or a short email, then a written quote for your books and your 2025 to 2026 return.
A written quote before any work starts
Hours: Monday to Friday, 9am to 5pm UK time.