Important: FilingFriend provides general informational guidance about UK filing requirements. It does not provide tax, accounting, or legal advice. Always confirm requirements with HMRC or Companies House.
Start with the right HMRC route
HMRC has different registration routes depending on whether you are self-employed, not self-employed but need a return, or already have a Unique Taxpayer Reference. Use the GOV.UK registration page to pick the right path.
If you are starting self-employment, HMRC may also ask for details such as the date you started trading and the nature of your business.
Allow time for account setup
Registration is not just one click. You may need to confirm identity, wait for account details, and set up online access before you can file.
That is why filing season is the wrong time to start thinking about registration for the first time.
What happens after you register
After registration, you still need to keep records, complete the tax return, and pay on time. Registration is the start of the process, not the whole process.
Once you know your first filing deadline, work backwards and set reminders well before January.
Key deadlines
| Action | Deadline | Why it matters |
|---|---|---|
| Start registration process | As soon as you know you will need to file | Early action gives you time for setup and identity checks. |
| Tell HMRC you need Self Assessment | 5 October after the relevant tax year | This is the standard HMRC registration deadline. |
| File your first online tax return and pay tax due | 31 January after the tax year ends | The registration step does not move the filing deadline. |
Official references
FAQ
What do I need before I register?
The exact details depend on your route, but HMRC will usually need personal details and information about why you need to file.
Should I wait until January to register?
No. January is usually the busiest point in the process. Register earlier so you have time to receive account details and prepare the return.
Next step
Keep the main dates visible
Use the FilingFriend calendar as a quick reminder layer, then return to this guide when you need the fuller explanation or official source links.