Side Hustle Tax UK: What Online Sellers Need to Know in 2026

If you sell on eBay, Vinted, Etsy, Depop or anywhere else online, HMRC almost certainly already has visibility of it, even if you’ve never registered as self-employed. Since January 2024, online marketplaces have had to report seller data to HMRC, and the rules catch far more casual sellers than most people realise. Here’s what actually applies in 2026, and when you do and don’t need to worry about it.

What Are Platforms Actually Reporting?

Under HMRC’s digital platform reporting rules, marketplaces like eBay, Vinted, Etsy and Depop have to report your sales activity to HMRC unless you’re under both of these in a 12-month period: fewer than 30 items sold, and less than £1,700 in revenue received. Cross either one, not just the sales count, and your activity can be reported. Reports cover the calendar year and are due to HMRC by 31 January each year, so the platforms are reporting on the previous year’s activity around the same time you’re filing your own Self Assessment.

Does This Mean I Owe Tax?

Not automatically. If you’re just clearing out your wardrobe or selling things you already owned personally, that’s not trading, and there’s no tax to pay regardless of how many items or how much money is involved. The reporting rules are about visibility, not a new tax. What actually creates a tax liability is trading: buying or making things specifically to resell for profit, on a regular basis.

The £1,000 Trading Allowance

If you are trading, the first £1,000 of income each tax year is covered by the Trading Allowance and doesn’t need to be declared at all. Go over £1,000 and you need to register for Self Assessment and declare your income, though you can still choose to deduct the £1,000 allowance instead of your actual expenses if that works out better for you.

What This Looks Like in Practice

Sell your own old clothes on Vinted a few times a year: no tax, no registration needed, even if a platform reports the sales to HMRC. Buy stock regularly to resell on eBay or Depop and turn over more than £1,000 a year doing it: you need to register for Self Assessment and declare the income, trading allowance aside. The platform reporting itself doesn’t change which of these you are, it just means HMRC now has the data to check.

What to Do If You Think You’re Affected

If you’ve been trading and haven’t registered, the sooner you sort it the better, HMRC is far more lenient with sellers who come forward than with ones who wait to be chased. Pull together your sales history from each platform, work out what’s actually trading income versus personal items sold, and register for Self Assessment if you’re over the £1,000 allowance.

Final Thoughts

The “side hustle tax” isn’t really a new tax at all, it’s the same rules that have always applied to trading income, just with HMRC now getting the sales data directly from the platforms instead of relying on people to self-report. If you’re not sure whether what you’re doing counts as trading, or you’ve had a report letter from a platform and want to know where you stand, it’s worth getting it checked properly rather than guessing.

Not sure if your side hustle counts as trading? Get a free Self Assessment review and find out exactly where you stand