Do I need to register if I earn less than £1,000 from a side hustle?

No. The HMRC trading allowance covers gross side-hustle income up to £1,000 per tax year — you don't need to register for Self Assessment, file a return or pay tax on it. The moment you cross £1,000 gross, registration is mandatory.

Can I claim expenses if I use the £1,000 trading allowance?

No — it's one or the other. Either claim the £1,000 trading allowance flat (no expenses deductible), or claim actual allowable expenses against your gross income. Above £1,000 with high expenses, claiming actuals usually wins.

When is the Self Assessment deadline in 2026?

For income earned in the 6 April 2025-5 April 2026 tax year: register by 5 October 2026, file paper returns by 31 October 2026, and file online + pay tax by 31 January 2027. Payments on account follow on 31 July 2027.

Do I pay National Insurance on side-hustle income?

Yes, once profit exceeds £12,570/yr you'll pay Class 4 NI (6% on profit £12,570-£50,270, 2% above). Class 2 NI becomes voluntary above £6,725 — most freelancers pay it because it cheaply preserves state pension entitlement.

What counts as an allowable side-hustle expense in the UK?

Anything 'wholly and exclusively' for the trade: software subscriptions, equipment depreciation, business-use proportion of phone and internet, professional insurance, accountancy fees, mileage at HMRC-approved rates, and a flat-rate working-from-home allowance.

Will my employer find out about my side hustle?

HMRC won't tell them — Self Assessment is private to you. But check your employment contract for any clauses on outside work or competition. If you're a full-time employee with PAYE, your tax code may shift slightly to collect the side-tax through payroll, which a curious payroll team could spot.

🇬🇧 United Kingdom · 2026 guide

Side hustle tax in the UK (2026 guide)

HMRC's trading allowance lets you keep your first £1,000 of side income tax-free. Above that, Self Assessment is the gate every UK side hustler walks through — and the deadlines are unforgiving.

Editorial guide · Hustle Report · authority: HM Revenue & Customs (HMRC)

When you have to register with HMRC

Threshold

£1,000 / tax year

If your gross side-hustle income exceeds £1,000 in a tax year (6 April → 5 April), you must register for Self Assessment and submit a return. Below that, the trading allowance covers you — no return, no tax. The threshold is gross revenue, not profit, so a £1,200 gross with £400 of expenses still triggers registration.

What you owe once you're over the line

Side-hustle profit is added to your employment income, then taxed at your marginal rate. National Insurance kicks in separately on the self-employment slice.

Income tax: 20% basic / 40% higher / 45% additional rate, charged on profit (revenue minus allowable expenses).
Class 4 National Insurance: 6% on profits between £12,570 and £50,270, then 2% above that (2025-26 rates).
Class 2 NI: voluntary above £6,725 of profit; usually worth paying for state pension credit.

How to register and file

Step 01
Register for Self Assessment
Sign up at gov.uk by 5 October following the tax year you crossed £1,000. You'll get a Unique Taxpayer Reference (UTR) by post within 10 working days.
Step 02
Track income and expenses monthly
Keep invoices, bank-statement evidence and any allowable expenses (subscriptions, equipment, mileage). HMRC expects 5 years of records — a labelled folder per tax year is enough.
Step 03
File your return online by 31 January
The deadline is 31 January after the tax year ends — so 31 January 2027 for income earned 6 April 2025-5 April 2026. Pay any balancing tax + first payment on account by the same date.
Step 04
Plan for payments on account
If your tax bill exceeds £1,000, HMRC asks you to pay 50% upfront for the next year too — meaning your January bill is effectively 1.5x. Set the cash aside as you earn.

Worked example

You're a UK PAYE employee on £55,000/yr. You take 12 freelance design briefs in 2025-26 at £400 each = £4,800. Allowable expenses (subs, half your home internet, a new laptop) come to £900.

Gross side income

£4,800

Tax + NI on profit

≈ £1,560

Profit £3,900 is taxed at 40% (you're already in the higher band) plus 2% Class 4 NI = roughly £1,640 owed. Net side cash: ~£3,160. The Hustle Report rate calculator factors all of this so you quote with eyes open.

Common pitfalls

Forgetting that revenue ≠ profit when checking the £1,000 threshold
The trading allowance test is on gross income, but tax is paid on profit. A side hustle bringing in £4,000 with £2,500 of legitimate expenses still requires a return — but you'll only owe tax on £1,500.
Missing the 31 October paper deadline if you're not online
Paper returns are due 31 October, three months earlier than online. If you've never filed and want to use a paper return, register the moment you cross the threshold.
Treating client refunds as 'not income'
HMRC counts every payment received in the tax year, even if you later refund it. Refunds become an expense in the year they're paid out, not a deduction from the original revenue.

From tax to take-home

Knowing the tax floor is the first half of the calculation. The second half is what to charge in the first place — so the post-tax number you see in your bank account actually moves the needle.

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FAQ

Side hustle tax in United Kingdom · FAQ

Do I need to register if I earn less than £1,000 from a side hustle?
No. The HMRC trading allowance covers gross side-hustle income up to £1,000 per tax year — you don't need to register for Self Assessment, file a return or pay tax on it. The moment you cross £1,000 gross, registration is mandatory.
Can I claim expenses if I use the £1,000 trading allowance?
No — it's one or the other. Either claim the £1,000 trading allowance flat (no expenses deductible), or claim actual allowable expenses against your gross income. Above £1,000 with high expenses, claiming actuals usually wins.
When is the Self Assessment deadline in 2026?
For income earned in the 6 April 2025-5 April 2026 tax year: register by 5 October 2026, file paper returns by 31 October 2026, and file online + pay tax by 31 January 2027. Payments on account follow on 31 July 2027.
Do I pay National Insurance on side-hustle income?
Yes, once profit exceeds £12,570/yr you'll pay Class 4 NI (6% on profit £12,570-£50,270, 2% above). Class 2 NI becomes voluntary above £6,725 — most freelancers pay it because it cheaply preserves state pension entitlement.
What counts as an allowable side-hustle expense in the UK?
Anything 'wholly and exclusively' for the trade: software subscriptions, equipment depreciation, business-use proportion of phone and internet, professional insurance, accountancy fees, mileage at HMRC-approved rates, and a flat-rate working-from-home allowance.
Will my employer find out about my side hustle?
HMRC won't tell them — Self Assessment is private to you. But check your employment contract for any clauses on outside work or competition. If you're a full-time employee with PAYE, your tax code may shift slightly to collect the side-tax through payroll, which a curious payroll team could spot.

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Editorial guidance, not tax advice. Numbers verified against the relevant authority as of Q1 2026 and refresh annually. For your specific situation — especially complex deductions, cross-border income or incorporation decisions — consult a chartered accountant or tax practitioner authorised in your jurisdiction.