Side hustles have gone from a nice-to-have to a necessity for a lot of people in the UK. Whether you are selling handmade jewellery on Etsy, picking up freelance web design jobs, tutoring students after work, walking dogs through an app, or renting out your spare room on Airbnb — chances are you know someone who is earning a bit of money on the side. Maybe that someone is you.
The problem is, once you start earning extra money, tax is not far behind. And for most people, the rules around side-hustle tax feel confusing, scary, and really easy to get wrong. You might have heard things like "you don't need to pay tax if it's under a grand" or "HMRC won't notice small amounts." Some of that is partly true. Some of it is completely wrong.
So let us clear it all up. In this guide, we will explain exactly how tax works when you earn extra income alongside your main job, what you need to report, what you can claim back, and how to make sure you are not caught out.
The £1,000 Trading Allowance — Your Free Pass (Sort Of)
The good news is that HMRC gives everyone a £1,000 tax-free trading allowance. This means if your total side-hustle income — not profit, but total income before expenses — is under £1,000 in a tax year, you do not need to tell HMRC about it at all. You do not need to register for Self Assessment. You do not need to file a tax return. It is completely tax-free.
This covers things like occasional sales on eBay, a bit of casual freelancing, or selling cakes at the local market now and then. As long as the total stays under a grand, you are fine.
But the moment you go over £1,000, things change. You will need to register as self-employed with HMRC and file a Self Assessment tax return each year. That might sound daunting, but honestly, it is not as bad as it sounds once you understand the basics.
Do You Need to Register as Self-Employed?
If your side-hustle income goes above £1,000 in a tax year (which runs from 6 April to 5 April the following year), you need to register for Self Assessment with HMRC. The deadline for registering is 5 October after the end of the tax year you need to report on.
So if you started earning over £1,000 from a side hustle in the 2025/26 tax year, you would need to register by 5 October 2026. But honestly, it is much better to register as soon as you realise you are going to go over that threshold. Leaving it to the last minute just adds stress.
Registering is free and you can do it online through the HMRC website. They will send you a Unique Taxpayer Reference (UTR) number, which you will need when you file your tax return. It can take a couple of weeks to arrive, so do not leave it too late.
How Much Tax Will You Actually Pay?
This is the question everyone asks first. The answer depends on how much you earn in total — from your day job and your side hustle combined.
In the 2025/26 tax year, the personal allowance is £12,570. That is the amount you can earn before paying any income tax. If you are employed, your employer is already using up some or all of that allowance through your PAYE tax code.
Your side-hustle profits get added on top of your employment income. So if you earn £30,000 from your day job and make £5,000 profit from your side hustle, your total taxable income is £35,000. You will pay 20% income tax on the side-hustle portion (since it falls within the basic rate band).
If your combined income pushes you over £50,270, the portion above that threshold gets taxed at 40%. That is the higher rate, and it can come as a nasty surprise if you were not expecting it.
Here is a quick example to make it clearer:
- Day job salary: £45,000
- Side hustle profit: £8,000
- Total income: £53,000
- Income over the higher-rate threshold (£50,270): £2,730
- Tax on that £2,730 at 40%: £1,092
- Tax on the remaining £5,270 of side income at 20%: £1,054
- Total extra tax from side hustle: roughly £2,146
That is before National Insurance as well. If your side-hustle profits are above £12,570, you will pay Class 4 National Insurance at 6% on profits between £12,570 and £50,270, and 2% above that. If your profits are lower than your personal allowance, you probably will not owe any NI on the side income — but it depends on your specific situation. Our National Insurance calculator can help you estimate what you owe.
What Expenses Can You Claim?
This is where a lot of people leave money on the table. When you are self-employed — even as a side hustle — you can deduct allowable business expenses from your income before calculating tax. That means you only pay tax on your profit, not your total earnings.
Common expenses you can claim include:
- Materials and stock — anything you buy to make or sell your products
- Software and subscriptions — Canva, Shopify, accounting software, web hosting
- Travel costs — fuel, train tickets, or mileage if you drive for business
- Phone and internet — the business portion of your bills
- Home office costs — if you work from home, you can claim a flat rate of £6 per week (£312 a year) without needing receipts, or calculate the actual proportion of your household bills
- Advertising — social media ads, flyers, website costs
- Professional fees — accountant fees, insurance, trade memberships
Keep receipts and records for everything. HMRC can ask to see them, and if you cannot prove an expense, they might not allow it. A simple spreadsheet or an app like FreeAgent or QuickBooks is more than enough for most people.
When Do You File and Pay?
The tax year runs from 6 April to 5 April. After the year ends, you need to file a Self Assessment tax return. There are two deadlines:
- Paper returns: 31 October (but almost nobody does paper anymore)
- Online returns: 31 January the following year
So for the 2025/26 tax year (ending 5 April 2026), your online tax return must be filed by 31 January 2027. Any tax you owe also needs to be paid by that date.
If you owe more than £1,000 in tax, HMRC may ask you to make "payments on account" — which are basically advance payments towards next year's tax bill. This catches a lot of people off guard in their second year of self-employment, because you might have to pay last year's tax bill plus half of next year's estimated bill at the same time.
What About Selling on eBay, Vinted, or Depop?
This is a really common question. If you are just clearing out your wardrobe or selling old stuff you no longer want, that is generally not taxable. HMRC treats this as selling personal possessions, and there is no tax to pay.
But if you are buying items specifically to resell at a profit — like buying clothes at car boot sales and flipping them on Vinted — that counts as trading. The £1,000 trading allowance applies, and if you go above it, you need to register and report it.
Since January 2024, platforms like eBay, Vinted, Etsy, and Airbnb are required to report seller data to HMRC if you make more than 30 sales or earn over €2,000 in a year. This does not mean you automatically owe tax — it just means HMRC has visibility of your activity. So it is worth making sure your records match up.
The Rent-a-Room Scheme
If your side income comes from renting out a furnished room in your home (through Airbnb or to a lodger), you get a separate tax-free allowance of £7,500 per year under the Rent-a-Room scheme. This is on top of the £1,000 trading allowance and applies specifically to income from letting out a room in your main home.
If you earn less than £7,500 from renting a room, you pay no tax on it and do not need to report it. Over £7,500, you either pay tax on the amount above the threshold or opt to report your actual income minus expenses — whichever works out better for you.
Tips to Keep Things Simple
Open a separate bank account. You do not legally have to, but it makes tracking income and expenses so much easier. Most digital banks let you open a business account for free.
Set aside money for tax. A good rule of thumb is to put 25-30% of your side-hustle profit into a savings pot for tax. That way, you are never scrambling to find the money when the bill arrives in January.
Use our calculators. If you want to see how your side-hustle income affects your overall tax bill, our salary calculator lets you plug in your numbers and see the breakdown instantly. It factors in income tax, National Insurance, and other deductions so you know exactly where you stand. If you are paid hourly for your side work, our hourly rate calculator can quickly show what your time is really worth after tax.
Do not panic. The system is designed for ordinary people, not just accountants. Thousands of people file Self Assessment for the first time every year, and most find it a lot less painful than they expected.
The Bottom Line
Having a side hustle is a brilliant way to earn extra money, build new skills, or test out a business idea. The tax side of things does not need to be a barrier. Once you know the basics — the £1,000 allowance, how to register, what expenses to claim, and when to file — it becomes just another part of running your little operation.
The biggest mistake people make is ignoring it and hoping HMRC will not notice. They will. Platforms are reporting your earnings, and HMRC's systems are getting better at matching data. The good news is that if you stay on top of it, the process is straightforward and you will never have a nasty surprise.
Use our free tax calculator to work out how your extra income affects your take-home pay, and start the new tax year with a clear picture of where your money goes.