What does your side hustle actually net you?

Most calculators treat self-employment as your only income. This one factors in your PAYE salary too, since that's what actually decides your rate.

These rates are provisional, based on early Budget announcements, and may change before the year starts.
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Turnover under £1,000 means you likely owe no tax or NI on it at all, and in most cases don't need to report it. The trading allowance covers it automatically.
Heads up: Payments on Account. Once your self-assessment bill goes over £1,000, HMRC usually asks for two advance payments toward next year's tax (50% each, due 31 January and 31 July). Your first bill can be nearly double what you expect, so it's worth setting extra aside.
You keep from your side hustle
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Tap an entry above for a plain-English breakdown

Estimate only, not tax advice. Income Tax shown is the extra tax caused by adding your side-hustle profit on top of your salary, not your total tax bill. Excludes voluntary Class 2 NI. Verify at gov.uk before filing.

Common questions
Yes, if your total income from it goes over £1,000 a year, before expenses. This applies whether you're selling on Vinted, eBay, or Etsy, freelancing, or doing casual work. Under £1,000, the trading allowance usually means you owe nothing and don't need to tell HMRC at all.
The first £1,000 of income from self-employment or a side hustle each tax year is covered by the trading allowance, tax free. Above that, you'll need to register with HMRC and declare it, even if you don't end up owing much once your personal allowance and expenses are factored in.
No, but it can feel that way. Your side-hustle profit gets added to your salary for Income Tax purposes, and since your personal allowance is usually already used up by your job, most of your side-hustle profit ends up taxed at your marginal rate, the same rate as the top slice of your salary. It's one combined bill, not two separate ones.
It depends on whether you're trading, not on how much the total comes to. Selling your own clothes, furniture, or unwanted belongings, even well over £1,000 in total, generally isn't taxable, since you're not running a business, you're just clearing things out. The £1,000 trading allowance only applies if you're buying or making things specifically to resell at a profit. Platforms are required to share seller data with HMRC once you pass certain thresholds, but that's just reporting, not proof you owe anything. The one rare exception is a single personal item sold for more than £6,000, which could trigger Capital Gains Tax on the gain.
Yes, once your side-hustle income goes over £1,000 in a tax year. You'll need to register with HMRC by 5 October following the end of the tax year you started earning above that threshold, then file a Self Assessment return by 31 January.
They're both collected through the same Self Assessment return, so in practice it's one bill and one deadline. Income Tax is based on your combined income, salary plus side hustle, while Class 4 National Insurance is calculated on your side-hustle profit alone.
Yes, you can deduct costs that are wholly for the business, like materials, postage, platform fees, or a share of your phone bill if you use it for work. You can either claim your actual expenses or use the £1,000 trading allowance instead, whichever works out better, not both.
HMRC increasingly receives seller and earnings data directly from platforms like eBay, Vinted, Airbnb, and Etsy, so undeclared income is more likely to be flagged than it used to be. Penalties depend on how much tax is owed and whether it looks deliberate, so it's far cheaper to register and file on time, even if your bill ends up small.
Your Self Assessment bill for a tax year is due by 31 January after it ends, for example by 31 January 2028 for the 2026/27 tax year. If your bill is over £1,000, HMRC usually also asks for payments on account toward the following year, due in January and July.