Most casual resellers don't realise they may have UK tax obligations. Here's a plain-English breakdown of what HMRC expects, when you need to declare, and how to prepare.
The "trading allowance" gives most casual resellers a free pass up to £1,000 of gross profit. Beyond that, HMRC expects you to declare. Here's the full picture — in plain English, not accountant speak.
Disclaimer: This guide is educational only. Tax rules change and individual circumstances vary. Consult a qualified accountant before filing a Self Assessment return.
HMRC's trading allowance means you can earn up to £1,000 gross per tax year from selling your own belongings or small-scale trading without needing to declare it or pay tax on it.
This covers:
This does NOT cover:
If you're running auction lots, buying to resell, or operating systematically — you're a trader in HMRC's eyes, regardless of profit amount.
You must register for Self Assessment (and file a tax return) if your trading profit — not just revenue — exceeds £1,000 per tax year. For most active resellers hitting £3,000–£10,000 in annual profit, this is mandatory.
The deadline to register is 5 October following the end of the tax year in which you hit the threshold.
Ignoring this can result in automatic penalties (starting at £100 for late filing), plus interest on unpaid tax.
As a trader, you can deduct legitimate business expenses from your revenue before calculating taxable profit. This is significant.
Allowable expenses for resellers:
| Expense | Notes | |---------|-------| | Stock cost | Hammer price + buyer's premium + VAT on premium | | Postage (outgoing) | Royal Mail, courier costs when selling | | Packaging | Boxes, bubble wrap, tape, poly mailers | | Platform fees | eBay, Vinted, Depop, Etsy, Stripe fees | | Auction bidding registration fees | Where charged | | Mileage | Car boot runs, post office trips, auction collection (45p/mile HMRC approved rate) | | Subscriptions | Arbitrage AI, cross-listing tools, bookkeeping software | | Phone & internet | Proportion used for business (estimate honestly — 20–50% is typical) | | Storage | Rent for external storage if used | | Photography equipment | Proportion used for listing photos |
Not allowable:
HMRC's approved mileage rate is 45p per mile for the first 10,000 miles in a tax year (25p after that). If you drive to auction collections, car boots, or the post office regularly, this adds up fast.
10 post office runs per month × 4 miles round trip = 40 miles/month × 12 = 480 miles × 45p = £216 tax deduction per year.
Log every business trip: date, destination, purpose, miles. The Arbitrage AI expense tracker has a mileage category that calculates the HMRC rate automatically.
If your trading profit (after expenses) exceeds approximately £12,570 (the personal allowance), you'll pay:
For most part-time resellers with profits under £12,570, you'll pay zero income tax (it falls within the personal allowance) and minimal NI.
If your gross turnover (total sales value, not profit) exceeds £90,000 in any rolling 12-month period, you must register for VAT.
For most resellers this is a distant concern. But if you're scaling quickly — particularly with high-volume clothing or electronics — monitor it. The Profit Tracker shows your running total revenue with a warning when you approach £75,000.
VAT registration has upsides and downsides. You can reclaim VAT on business purchases. But you must charge VAT on sales, which reduces your competitiveness unless selling B2B.
The Arbitrage AI tax export (Tracker → Export CSV) produces a HMRC-ready breakdown of:
File this with a qualified accountant or enter the figures directly into your HMRC Self Assessment online form at gov.uk/self-assessment-tax-returns.
| Date | Action | |------|--------| | 5 April | End of UK tax year | | 5 October | Deadline to register for Self Assessment (new traders) | | 31 January | Online Self Assessment filing deadline | | 31 January | Payment deadline for tax owed |
Key takeaway: If you're buying to resell regularly, you're a trader in HMRC's eyes. Track all income and expenses from day one. The £1,000 trading allowance only protects casual sellers of personal belongings. Use the CSV export to make your annual return straightforward. Consult an accountant if in doubt.
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