Class 4 National Insurance for resellers, explained
When people work out the tax on their reselling, they often forget National Insurance. If you are self-employed and your profits are high enough, you may pay Class 4 National Insurance on top of income tax. Here is how it works, simply.
General information, not tax advice. Check with HMRC or a qualified accountant before you act on it.
What Class 4 National Insurance is
Class 4 National Insurance is a contribution the self-employed pay on their profits, separate from income tax. It only applies once your profit passes a threshold, so a lot of smaller resellers never pay it.
When you pay it
You pay Class 4 on your trading profit above the threshold, which is £12,570 for the 2026/27 tax year, the same figure as the personal allowance. If your reselling profit is under that, you normally pay no Class 4 at all.
It is only on the trading profit
Class 4 is charged on your self-employed profit, not on your job salary. So if you have a day job, your salary does not count towards the Class 4 threshold. Only your reselling profit does. That means many part-time resellers stay under it even if their total income is higher.
How it sits with income tax
Income tax and Class 4 are worked out separately but on the same profit. Once your profit passes the threshold, you can have both a small income tax amount and a small Class 4 amount. Both are estimates until you file, and both come off the same profit figure.
The simple version
If your reselling profit is under £12,570, you almost certainly pay no Class 4. Over it, you pay a small percentage on the profit above the threshold, on top of income tax. This is general information, not tax advice, so check your own figures with HMRC or an accountant.
Frequently asked questions
Do I pay National Insurance on my reselling?
Only Class 4, and only if your trading profit passes £12,570 in a tax year. Under that, you normally pay no Class 4.
Does my day job count towards Class 4?
No. Class 4 is charged on your self-employed profit only, not your salary, so your job income does not count towards the threshold.
Is Class 4 on top of income tax?
Yes. Once your profit is over the threshold, Class 4 is worked out separately and added on top of any income tax, on the same profit.
See where you actually stand
Get a rough answer in about a minute with the free calculator, or connect your eBay account to see your real profit and tax.
Related guides
This guide is general information, not tax advice, and reflects the UK rules for the current tax year. Always check with a qualified accountant before you file. FlipTally is independent and not affiliated with, endorsed by or connected to eBay, Vinted, Depop or HMRC. Last updated 2026-08-04.