How to Work Legally as a Self-Employed Freelancer in the UK (2025)

Becoming self-employed in the UK gives you freedom — but it also comes with legal responsibilities. To avoid HMRC fines or problems with clients, it’s essential to set yourself up properly.

Here’s what every UK freelancer or sole trader needs to do to work legally in 2025.


✅ 1. Register with HMRC as Self-Employed

If you earn more than £1,000 from self-employment in a tax year, you must register with HMRC.

How to register:

  • Sign up for a Government Gateway account
  • Register for Self Assessment online
  • Receive your Unique Taxpayer Reference (UTR) in the post

You need to register by 5th October after the end of the tax year you started trading.

✅ 2. Keep Accurate Records

You must track:

  • All income from clients
  • Business expenses and receipts
  • Mileage and travel (if claiming)

Tip: Use accounting software to simplify this.

👉 Explore the best free accounting tools for freelancers

✅ 3. File a Self Assessment Tax Return

Each year, you must:

  • Complete your tax return online
  • Declare your income and expenses
  • Pay Income Tax and National Insurance owed

The deadline for online returns is 31st January following the tax year.

✅ 4. Consider Business Insurance

While not always legally required, freelancer insurance gives you peace of mind. For some industries (e.g., security, consulting), clients may require proof of cover.

👉 Compare trusted freelancer insurance options

✅ 5. Stay Informed About Self-Employment Rules

Tax and business rules change regularly in the UK. Stay up to date to avoid penalties.

👉 Check our full Self-Employment Guide

📌 Final Thoughts

Working legally as a freelancer in the UK isn’t complicated — but missing key steps can cause major headaches. Register properly, keep good records, and stay organised to keep your business running smoothly.

Next Steps for UK Freelancers

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