Self Assessment for Resellers: A Checklist Before 31 January

If you resell for profit in the UK and your sales went over £1,000 between 6 April 2025 and 5 April 2026, you probably need to file a Self Assessment tax return for that year. The deadline to file online and pay is 31 January 2027. This checklist covers what to gather, what you can deduct and the mistakes resellers make most often.

This is general information, not tax advice. If your situation is complicated, an accountant is worth the fee.

Do you need to file at all?

Selling your own unwanted things, like clothes you've worn or a games console you no longer use, is usually not trading, and you don't pay Income Tax on it. Buying things in order to sell them at a profit is trading.

For trading income, the first £1,000 a tax year is covered by the trading allowance. That's £1,000 of sales, not profit. If your total sales were £1,000 or less, you don't need to tell HMRC about them. Above that, you file a return.

Not sure which side you're on? The selling limit checker tells you whether your platforms will report you and whether the trading allowance covers you.

HMRC may already know what you sold

Since January 2024, Vinted, eBay, Depop and other platforms collect details of sellers who make 30 or more sales, or receive more than €2,000 (about £1,700), in a calendar year. They send these to HMRC each January under the reporting rules for digital platforms. A report doesn't mean you owe tax, but the figures on your return should make sense next to it.

The checklist

1. Register if this is your first return

If you've never filed before, you need to register for Self Assessment as self-employed and get a Unique Taxpayer Reference (UTR). The deadline to register for 2025/26 was 5 October 2026. If you missed it, register now: the letter with your UTR can take a couple of weeks to arrive.

2. Total your sales for the tax year

Use 6 April 2025 to 5 April 2026, not the calendar year. Download the sales reports from each platform you sell on and add them up. Count what buyers paid you for items, and postage if they paid it to you. Don't count the buyer protection fees that Vinted or eBay charge buyers on top: you never received that money.

3. Gather your costs

You can deduct costs you had only because of your reselling. For most resellers that means:

• the stock you bought to resell
• platform fees, payment processing and promoted listings
• postage and packaging you paid
• cleaning, repairs and authentication
• tools and subscriptions you use for the business, such as an inventory app or a label printer
• a share of your phone and internet bills

If you work from home for 25 hours or more a month, you can claim a flat rate for working from home instead of working out the real share of your bills: £10 a month for 25 to 50 hours, £18 for 51 to 100 hours and £26 for 101 hours or more.

4. Choose real costs or the £1,000 allowance

You can deduct either your real costs or the £1,000 trading allowance, not both. Most resellers spend more than £1,000 a year on stock alone, so real costs usually win. If you sell things you got cheaply or for free, the allowance can be better. The reseller tax calculator compares both and estimates the tax.

5. Know how your profit is counted

Since April 2024, cash basis is the standard way for sole traders to work out profit. You count money when you receive it and costs when you pay them. Stock you bought before 5 April counts as a cost in that year, even if it's still unsold. If you opted for traditional accounting instead, you need to value your unsold stock at the end of the year: our guide to valuing stock with FIFO shows how.

6. Work out what you'll pay

For 2025/26, your reselling profit is added to your other income. Income Tax is 20% on income between £12,570 and £50,270, and 40% above that (Scotland has its own bands). You also pay Class 4 National Insurance on profits over £12,570: 6% up to £50,270, then 2%.

If your bill is more than £1,000, HMRC usually asks for payments on account towards next year: half of this year's bill on 31 January and half on 31 July, on top of what you owe now. This catches out a lot of first-time filers, so set the money aside.

7. File and pay by 31 January 2027

If you file late, there is a £100 penalty straight away, even if you owe no tax, and more the longer it runs. Interest is charged on tax paid late.

8. Keep your records

Keep your sales reports, receipts and bank statements for at least 5 years after the 31 January deadline. For a 2025/26 return, that means until January 2032. Screenshots of platform orders are fine, but a record of what you paid for each item is what HMRC is most likely to ask for.

Mistakes to avoid

• Reporting profit as sales. The return asks for your turnover (total sales) and your costs separately. Don't net them off before you enter them.
• Forgetting fees. Platform and payment fees add up to hundreds of pounds a year for an active seller, and they're all deductible.
• Mixing personal sales with stock. If you also sold your own old things, keep them out of your trading figures. If you sold a personal possession for more than £6,000, the chattels CGT calculator shows whether Capital Gains Tax applies.
• Leaving it until the last week. Gathering a year of sales from three platforms takes longer than filing.

Make next year easier

The work is in step 2 and step 3: totalling a year of sales and finding what you paid for each item. If you record every item, sale and fee as it happens, in a spreadsheet or an inventory app, next January's return is a matter of reading off the totals.