Freelance Tax UK: Self-Assessment, Expenses, and MTD Explained

If you earn more than £1,000 from freelancing in a tax year, you need to register with HMRC as self-employed. This isn't optional — it's a legal requirement.

The good news: it takes about 10 minutes online.

1. Go to gov.uk/register-for-self-assessment
2. Create a Government Gateway account (if you don't have one)
3. Fill in the registration form — your name, address, what you do, when you started
4. You'll receive your UTR (Unique Taxpayer Reference) number by post within 10 working days

You need to register by 5 October following the end of the tax year in which you started freelancing. So if you started in September 2025, you'd register by 5 October 2026.

Important: Registration is separate from filing your tax return. You register once, then file a return every year by 31 January.

Every January, freelancers across the UK have a collective moment of panic. Self-assessment doesn't have to be stressful if you've been keeping decent records throughout the year.

Key dates:

• 6 April - 5 April — The UK tax year
• 31 October — Paper return deadline (don't do this, file online)
• 31 January — Online return deadline AND payment deadline
• 31 July — Second payment on account (if applicable)

What you'll need:

• Total income from all sources (freelance earnings, employment, investments)
• Total business expenses (more on this below)
• Any student loan repayments due
• Your UTR number

The actual form isn't as scary as it looks. If your freelancing is straightforward (sole trader, no employees, UK-based), the self-employment section is just income minus expenses. HMRC calculates your tax.

This is where most freelancers leave money on the table. If an expense is "wholly and exclusively" for business, you can deduct it from your income before calculating tax.

Common freelancer expenses:

• Equipment — Laptop, monitor, desk, chair, software subscriptions (including OwnedWork Pro)
• Office costs — Stationery, printer ink, phone bills (business portion)
• Travel — Client meetings, networking events. 45p per mile for the first 10,000 miles if using your own car
• Working from home — Use the simplified method: £6/week flat rate (no receipts needed) or calculate the actual proportion of household bills used for business
• Professional development — Courses, books, conferences directly related to your work
• Marketing — Website hosting, domain names, business cards, advertising
• Professional services — Accountant fees, legal advice, insurance
• Bank charges — Monthly fees on your business bank account

Keep receipts for everything. Digital copies are fine — photograph them the day you get them. HMRC can ask to see receipts for up to 5 years after the relevant tax year.

As a self-employed freelancer, you pay two types of National Insurance:

• Class 2 — A flat rate of £3.45 per week (2025/26). You pay this if your profits exceed £12,570. It's collected through your self-assessment.
• Class 4 — 6% on profits between £12,570 and £50,270, then 2% on anything above that (2025/26 rates).

National Insurance contributions count towards your state pension and some benefits. Don't think of it purely as a cost — it's building your entitlement.

Tip: If you're employed AND freelancing, you might end up overpaying NI. You can apply for deferment of Class 2 and 4 NI if your combined contributions would exceed the annual maximum.

You must register for VAT if your taxable turnover exceeds £90,000 in any 12-month period (2025/26 threshold). You can also register voluntarily below this threshold.

Why would you register voluntarily?

• You can reclaim VAT on business purchases (equipment, software, etc.)
• It makes your business look more established to clients
• If you mainly work with VAT-registered businesses, they can reclaim the VAT you charge — so it's neutral for them

Why you might not want to:

• If your clients are consumers (not businesses), you'd effectively increase your prices by 20%
• More admin — you'll need to file VAT returns quarterly
• Record-keeping requirements increase

If you do register, look into the Flat Rate Scheme. It simplifies VAT by letting you pay a fixed percentage of your gross turnover instead of calculating VAT on every transaction. Most new freelancers get a 1% discount in their first year.

Making Tax Digital is HMRC's plan to move tax reporting online. Here's what it means for freelancers:

• From April 2026: Self-employed people with income over £50,000 must use MTD-compatible software to keep digital records and submit quarterly updates to HMRC
• From April 2027: The threshold drops to £30,000
• Below £30,000: No confirmed date yet, but it's coming eventually

What this means in practice:

• You'll need to use accounting or invoicing software that's MTD-compatible
• You'll submit income and expense summaries to HMRC every quarter (not a full tax return — just a summary)
• Your annual self-assessment will still exist but will be pre-populated with the quarterly data

If you're already using invoicing software like OwnedWork and keeping digital records, the transition should be relatively painless. The freelancers who'll struggle are the ones still using shoeboxes of receipts and annual spreadsheets.

HMRC requires you to keep records of all your income and expenses. The minimum you need:

• All invoices you send (with dates and amounts)
• All receipts for business expenses
• Bank statements for your business account
• Mileage log if you claim travel expenses

How long to keep them: 5 years after the 31 January filing deadline for the relevant tax year. So records for the 2025/26 tax year (filed by 31 January 2027) should be kept until 31 January 2032.

Digital records are perfectly acceptable. In fact, with MTD coming, they'll be required. Using an invoicing tool that stores your sent invoices and tracks your income automatically handles half the job.