24/06/2026
Most people selling a bit online have no idea this is happening.
Since January 2024, the platforms you sell or earn through - eBay, Vinted, Etsy, Depop, Airbnb, Uber, all of them - have to send your income straight to HMRC. By law.
And I don't mean a rough summary. I mean your name, your sales, your actual numbers.
As of this January, that whole data-sharing cycle has run its first full loop, and it feeds directly into HMRC's Connect system. The estimate is that up to five million people could be caught up in it.
Now here's the bit I really want you to hear.
This isn't a new tax. Nothing about what you owe has changed. What's changed is what HMRC can see. For years there was a gap between what you made on these apps and what HMRC actually knew about. That gap is gone.
So if you've got a little something on the side - a few hundred quid clearing out the wardrobe on Vinted, a spare room on Airbnb, the odd bit of freelance work through an app - chances are HMRC already has the figures. Before you've even filed.
And honestly, the side income is never the problem. The problem is a mismatch. If what you put on your return doesn't line up with what the platform has already told them, that's what gets you a letter. I've seen it triggered over gaps of less than £100.
Here's the reassuring part though: this is genuinely easy to get right. There's a £1,000 trading allowance, so the really small stuff is often nothing to worry about. And when you do declare properly, all that data matching actually works in your favour. It just quietly confirms you've done the right thing.
This is the whole point of having someone in your corner all year, not just in January. Not to scare you - to make sure your numbers are tidy and joined-up before HMRC's software ever takes a look.
Follow for more - no fluff, just what your accountant probably hasn't told you.