April 2026 5 min read

Side hustle tax guide: what you owe HMRC on your extra income

Whether you're selling on Etsy, freelancing in the evenings, or renting out a spare room, you might owe tax on your extra income. Here's how to stay on the right side of HMRC without overpaying.

Side hustle tax guide UK

Do You Need to Pay Tax on Your Side Hustle?

The short answer: it depends on how much you earn. The UK has a £1,000 trading allowance that lets you earn up to £1,000 from self-employment or casual trading without paying any tax or even telling HMRC.

If your side hustle income exceeds £1,000 in a tax year, you'll need to register for Self Assessment and file a tax return.

The £1,000 Trading Allowance

If your total trading income is £1,000 or less per tax year, it's completely tax-free. You don't need to register with HMRC or file a return.

If you earn more than £1,000, you can either deduct the £1,000 allowance instead of claiming actual expenses, or claim your actual expenses — whichever gives you a better result.

What Counts as Trading Income?

HMRC considers it trading income if you're regularly selling goods or services with the intention of making a profit. This includes:

What Doesn't Count

How to Register with HMRC

If your side hustle income exceeds £1,000, you need to:

  1. Register for Self Assessment on the HMRC website
  2. Register by 5 October after the end of the tax year in which you started trading
  3. File your tax return by 31 January (online) following the end of the tax year
  4. Pay any tax owed by 31 January

Don't Miss the Deadlines

Late registration and filing attract automatic penalties. A late tax return incurs an immediate £100 fine, and additional penalties accumulate for every month you delay. Set calendar reminders for 5 October (registration) and 31 January (filing and payment).

How Much Tax Will You Pay?

Your side hustle profits are added to your employment income to work out your total taxable income. The tax you pay depends on which income tax band your combined income falls into.

If Your Day Job Uses Your Personal Allowance

Most people with a full-time job have already used their £12,570 Personal Allowance. In this case, your side hustle profits are taxed from the first pound:

Example: Side Hustle Tax on £5,000 Profit

Sarah earns £35,000 from her day job and makes £5,000 profit from freelance graphic design.

  • Total income: £40,000 (all within the basic rate band)
  • Income tax on side hustle: £5,000 x 20% = £1,000
  • Class 4 NI: £5,000 x 6% = £300
  • Class 2 NI: £179.40
  • Total tax on side hustle: £1,479.40
  • She keeps: £5,000 - £1,479.40 = £3,520.60

Example: Side Hustle Pushing Into Higher Rate

James earns £48,000 from his day job and makes £8,000 profit from tutoring.

  • Total income: £56,000
  • First £2,270 of side hustle taxed at 20% (up to £50,270): £454
  • Remaining £5,730 taxed at 40%: £2,292
  • Class 4 NI at 6%: £480
  • Class 2 NI: £179.40
  • Total tax on side hustle: £3,405.40

Expenses You Can Claim

You can deduct allowable business expenses from your side hustle income to reduce your taxable profit. Common expenses include:

Working From Home

Equipment and Supplies

Travel

Marketing and Professional Services

Trading Allowance vs Actual Expenses

If your income is between £1,000 and about £2,000, you have a choice:

Method How It Works Best For
Trading Allowance Deduct £1,000 flat from your income Low expenses, simple side hustles
Actual Expenses Deduct your real business costs Higher expenses, equipment-heavy work

You can't use both — pick whichever reduces your taxable profit more.

The Rent-a-Room Scheme

If your side hustle involves renting out a furnished room in your home (including through Airbnb), the Rent a Room Scheme gives you a separate £7,500 tax-free allowance. This is completely separate from the £1,000 trading allowance.

Record Keeping

Even for a small side hustle, keep records of:

HMRC requires you to keep records for at least 5 years after the 31 January filing deadline. A simple spreadsheet tracking income and expenses each month is usually enough.

Common Mistakes to Avoid

The Bottom Line

A side hustle can be a great way to boost your income, and the tax system is actually quite generous for small earners with the £1,000 trading allowance. The key is to understand your obligations, register on time if you need to, and keep good records throughout the year.

If your side hustle grows beyond a few thousand pounds, consider speaking to an accountant — they'll often save you more in tax than they cost in fees.

Use our income tax calculator to estimate your total tax bill including side hustle income, or check our allowable expenses guide for more on what you can claim.

Back to all articles