The short answer is: if your gross side hustle income exceeded £1,000 in the tax year, yes. If it did not, no.
The longer answer involves understanding what gross income means, what the 5 October deadline requires of you, what the step-by-step registration process actually looks like, and — critically — what happens if you have already passed that deadline without registering.
This is one of the most-searched tax questions in the UK side hustle space, and most of the answers online are incomplete. This guide covers the full picture for the 2025/26 tax year (deadline 5 October 2026) and the 2026/27 tax year (deadline 5 October 2027).
The Registration Threshold — and What Gross Income Actually Means?
The trigger for registering as self-employed is crossing £1,000 in gross trading income in a tax year.
Gross Income is Not Profit
This is the single most important point in this article. HMRC’s £1,000 threshold is measured on gross income — the total amount paid to you before any deductions, expenses, or platform fees.
It is not your profit. It is not what the platform paid you after taking its cut. It is every pound buyers or clients paid you for goods or services.
Examples: You sell on Etsy and buyers paid £1,150 total. Etsy deducted £160 in fees and paid you £990. Your gross income is £1,150 — above the threshold. You do private tutoring and your clients paid you £800 total. Your gross income is £800 — below the threshold. You do Vinted reselling (£650) and dog walking (£420). Combined gross income: £1,070 — above the threshold, even though neither activity alone crossed £1,000.
The £1,000 Trading Allowance
Every UK individual has a £1,000 trading allowance per tax year. This allowance means that gross trading income below £1,000 is entirely exempt — no tax, no registration, no reporting required. Above £1,000, you must register and report, even if you ultimately owe no tax.
The Registration and Tax Liability Are Separate
Crossing the £1,000 threshold requires you to register. Whether you actually owe any tax depends on your total income situation. A person with no other income who earns £3,000 from tutoring may owe no income tax at all (because £3,000 minus the £1,000 trading allowance = £2,000 taxable profit, well below the £12,570 personal allowance). But they still must register and file a return.
Who Definitely Needs to Register?
You must register as self-employed with HMRC if any of the following apply in the tax year (6 April to 5 April):
Your total gross income from all self-employed activities combined exceeded £1,000. This includes Etsy, Vinted, eBay trading, freelancing, tutoring, delivery driving, dog walking, and any other self-employed income source.
You earned any amount as a self-employed partner in a business partnership (different rules from sole trader self-employment apply — see FAQ below).
You have other reasons to file a Self Assessment return, such as rental income, foreign income, or total income over £100,000 — in which case you add your side hustle income to your existing return.
Who Definitely Does Not Need to Register?
You do not need to register as self-employed if:
Your total gross trading income from all side hustles combined stayed below £1,000 in the tax year.
You sold personal possessions that you owned and used yourself — decluttering your wardrobe on Vinted, selling your own old electronics, clearing out books. HMRC’s test is whether you had a profit motive when acquiring the items. If you did not buy or make them specifically to resell, this is not trading income.
You earned investment income only (dividends, savings interest) — this is not trading income.
You are an employee who received a bonus, overtime, or commission — this is PAYE employment income, not self-employment.
The Making Tax Digital Change From April 2026
2026 introduces a significant change to how some self-employed people report their income. Making Tax Digital for Income Tax (MTD ITSA) began rolling out from 6 April 2026.
Who is Affected Now?
From April 2026, sole traders and landlords with combined gross business and property income over £50,000 per year must use MTD-compatible software to keep digital records and submit quarterly updates to HMRC, plus a final declaration. This replaces the traditional annual Self Assessment tax return for those above the threshold.
Who is Not Affected Yet?
The £50,000 threshold means the vast majority of side hustlers are unaffected by MTD until at least April 2027, when the threshold drops to £30,000. Below these thresholds, the traditional annual Self Assessment return continues as normal.
What This Means for New Registrants?
If you are registering as self-employed for the first time in 2026 and your income is below £50,000, you register and file in exactly the same way as before MTD. The MTD regime does not apply to you at current thresholds.
How to Register?: Step by Step
The registration process takes approximately 10–15 minutes online. Here is the exact process for 2026.
Step 1: Go to Gov.uk/Register-for-self-assessment
Navigate to gov.uk/register-for-self-assessment. Select “I need to register for Self Assessment” and choose “Self-employed or a sole trader” as your reason.
Step 2: Create or Log Into Your Government Gateway Account
If you already have a Government Gateway account — for example, to check your PAYE tax code, claim Child Benefit, or view your National Insurance record — log in with those credentials.
If you do not have one, create one. You need: an email address, and a form of identity verification (UK passport or driving licence details, or a recent P60, payslip, or tax credit correspondence as a fallback).
The identity verification step can fail on the first attempt for a significant number of users — typically because the details provided do not exactly match what HMRC holds. If this happens, use the alternative verification route with a payslip or P60.
Step 3: Complete the Sa1 or Cwf1 Form
HMRC’s online registration uses either the SA1 form (general Self Assessment registration) or the CWF1 form (specifically for new self-employment). The online system guides you to the correct form.
You will be asked for:
Your National Insurance number. Your date of birth and home address. Your business start date — the date you first received any trading income, even informally. Use the actual date you first earned money from the activity, not the date you decided to register.
Your business description — a brief description of what you do (“selling handmade goods online”, “tutoring”, “freelance graphic design”). You do not need a formal business name. Trading under your own name is standard for side hustlers.
Step 4: Submit and Wait for Your Utr
After submitting, HMRC posts your Unique Taxpayer Reference (UTR) to your registered address by second-class mail. This typically takes 10–14 working days. Some people report waiting up to 21 days.
Your UTR is a 10-digit number — for example, 1234567890. It is your permanent identifier for Self Assessment. Write it down somewhere accessible. You need it every January and every time you contact HMRC about your tax return.
Step 5: Activate Self Assessment in Your Government Gateway Account
Once your UTR arrives, log back into your Government Gateway account. Add Self Assessment to your account if it is not already listed. HMRC may send a second letter with an activation code — enter this code within 28 days of issue or you will need to request a replacement.
Important: there are two letters, two codes. The first is your UTR (issued automatically after registration). The second is the Government Gateway activation code (sometimes issued separately). Both are needed before you can file your return.
Total time from registration submission to having a fully active Self Assessment account: approximately 20–25 working days. This is why registering promptly matters — leaving it until late September for the 5 October deadline creates real risk of missing it if post is delayed.
Step 6: Keep Records From Day One
Once registered, you are required to keep records of all business income and expenses. For side hustlers, this means: a record of every payment received (date, source, amount), receipts or invoices for any business expenses you plan to claim, and bank statements showing business transactions.
Digital records in a spreadsheet are sufficient for most side hustlers. HMRC requires records to be kept for at least five years after the filing deadline for that tax year.
What Happens After You Register?
After registration and account activation, HMRC will:
Send you an annual Self Assessment return notification (either by post or to your online account) telling you that your return is due.
Expect you to file a return every January, even in years where your side hustle income falls back below £1,000 — unless you formally deregister.
Potentially adjust your PAYE tax code if you are also employed, to collect any extra tax due on your side hustle through your pay. This is called a coding adjustment.
Deregistering
If you stop trading or your income consistently stays below £1,000, you can ask HMRC to remove you from Self Assessment. Do this through your online account or by calling the Self Assessment helpline. Do not simply stop filing — HMRC will issue automatic late-filing penalties for missing returns on active accounts, even if income is zero.
What to Do if You Have Missed the Deadline?
The 5 October deadline for the 2025/26 tax year is 5 October 2026. If you crossed the threshold in 2025/26 and have not yet registered, register immediately. Do not wait.
The penalty for late registration is a “failure to notify” charge — a percentage of the tax owed, starting from the point registration was due. HMRC determines the penalty rate based on whether your failure was deliberate or simply a mistake, and whether you came forward voluntarily or were discovered.
Voluntary disclosure — registering and declaring income before HMRC contacts you — consistently results in significantly lower penalties than prompted disclosure. HMRC’s guidance is explicit: the sooner you come forward, the better the outcome.
For income from 2024/25 or earlier that was never declared, the voluntary disclosure process is available at gov.uk/make-a-voluntary-disclosure. Unprompted voluntary disclosure of innocent errors typically results in interest charges on unpaid tax rather than substantial penalties.
Frequently Asked Questions
Do I register as a sole trader or something else?
Most side hustlers register as sole traders — individuals trading in their own name. You do not need to form a limited company or register a business name. Simply select “self-employed sole trader” during the registration process. A business name is optional; most side hustlers trade under their own name without issue.
I have already registered for Self Assessment for a previous period of self-employment. Do I need to re-register?
If you have a UTR from previous self-employment, you may already be registered. Log into your Government Gateway account and check whether Self Assessment is still active.
If you were previously removed from Self Assessment when you stopped trading, you need to use the CWF1 form specifically (not the SA1) to restart self-employment within an existing Self Assessment account.
Does registering as self-employed mean I have to pay more tax?
Registration does not create a tax liability. Tax is owed based on your actual income and profit. Registering simply means HMRC is aware of your income and you file a return. If your total income remains below the personal allowance (£12,570), your tax bill is zero even after registering and filing.
I earn less than £1,000 but want to register voluntarily. Can I?
Yes. There is no minimum income requirement for registering. Some people register voluntarily because they want to make Class 2 National Insurance contributions (voluntary Class 2 NICs count toward qualifying years for the State Pension at £3.45/week for 2026/27) even when profits are low. This can be a financially sensible choice for younger side hustlers building their NI record.
Does HMRC know about my side hustle before I register?
Potentially, yes. Since January 2025, digital platforms including Etsy, Vinted, eBay, Deliveroo, Uber Eats, Amazon, and Airbnb have been required to report seller earnings to HMRC if sellers cross 30 transactions or approximately £1,700 in annual sales.
HMRC receives this data and cross-references it against Self Assessment records. If a platform has reported your earnings but you have not registered, you may receive a nudge letter.
What to Read Next?
Once registered, the next step is understanding how to actually file your return. See our guide on how to file your Self Assessment once registered for the full step-by-step filing process.
For a clear explanation of what counts as gross income and how the £1,000 allowance works, see our guide on how much you can earn before registration is required.
More in Tax, Legal & HMRC
Late Tax Penalties for UK Side Hustlers in 2026 (Real Costs)
HMRC’s penalty system for Self Assessment has two separate tracks that run simultaneously: late filing penalties (for not submitting your return on time) and late payment penalties (for not paying the tax owed on time). Missing both triggers charges from both tracks on top of each other. The total cost can escalate quickly. This article […]
VAT Registration for UK Side Hustles (2026 Threshold Rules)
Most UK side hustlers will never need to register for VAT. The threshold — £90,000 of taxable turnover in a rolling 12-month period — puts VAT registration firmly in the territory of a full-time business rather than a supplementary income stream.Someone tutoring for £2,000 a year, reselling clothes on Vinted for £3,000, or doing occasional […]