Register if you're self-employed

If you have to send a tax return and did not send one last year, you need to register for Self Assessment and Class 2 National Insurance. Register by 5 October in your business’s second tax year. You could be fined if you do not. If you’ve sent a return online before Re-register online (form CWF1) . You’ll need your 10-digit Unique Taxpayer Reference ( UTR ) from when you registered before. You can find your UTR if you do not know it. If you have not sent a return online before Register online . When you register, HM Revenue and Customs ( HMRC ) will: send you a letter with your 10-digit Unique Taxpayer Reference ( UTR ) set up your account for the Self Assessment online service If you already have a UTR (for example, if you’ve sent a paper return before or registered by phone), create an account for the online service instead. What happens next You’ll get a letter within 10 working days (21 days if you’re abroad) with an activation code for your online account. You’ll need this the first time you sign in. You can get a new activation code if you do not receive it or you lose it. Other ways to register You can fill this form on-screen then print off and post to HMRC . You’ll need to have all your information ready as you cannot save a partly completed form. If you’re using an older browser, for example Internet Explorer 8, you’ll need to update it or use a different browser. Find out more about browsers .

Register if you're not self-employed

If you have to send a tax return and did not send one last year, you need to register for Self Assessment by 5 October. Register now After you register You’ll get a letter containing your Unique Taxpayer Reference ( UTR ) within 10 working days (21 if you’re abroad). You need your UTR to send a return. If you’ve sent a Self Assessment tax return before, you’ll already have a UTR . If you do not know it, you can wait for the letter or find your UTR . If you’ve sent a return online before Once you’ve re-registered, sign in to your existing account to send a return. If you have not sent a return online before After you register, you’ll need to: create a new online account use your UTR to sign up for the Self Assessment service You’ll get an activation code in the post within 7 working days of signing up (21 if you’re abroad). When you get the code, sign in to send your return. You can replace an activation code if you do not receive it or you lose it.

Register if you're a partner or partnership

You must register for Self Assessment if you’re a partner in a partnership. You’ll need your partnership’s 10-digit Unique Taxpayer Reference ( UTR ). You can find a UTR if you’ve lost it. You must also register your partnership if you’re the ‘nominated partner’. There are different ways to register: for limited liability partnerships if you’re a partner that’s not an individual, for example a company or trust

Register for and file your Self Assessment tax return

File your tax return online

You can use the online service to:

fill in and send your tax return to HM Revenue and Customs (HMRC)
go back to a tax return you’ve already started
check your details, view returns and print your tax calculation

You’ll need to register for Self Assessment again if you’ve sent a tax return in the past but you did not have to send one last year.

This page is also available in Welsh (Cymraeg).

If you’re filing online for the first time

You must have received your Unique Taxpayer Reference (UTR), enrolled for the online service and activated your account using the code you received in the post.

How you do those things depends on whether you’re:

You’ll need to prove your identity using Government Gateway or GOV.UK Verify.

If you have not told HMRC you need to send a return

There are different ways to register for Self Assessment if you’re:

You should allow enough time to complete the registration process so you can send your return by the deadline.

When you cannot use the service

You need to use commercial software or download other forms to send a Self Assessment tax return:

for a partnership
for a trust or estate
if you lived abroad as a non-resident
to report multiple ‘chargeable gains’, for example from life insurance
if you get income from a trust, you’re a Lloyd’s underwriter or a religious minister

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Register for and file your Self Assessment tax return

File your tax return online

If you’re filing online for the first time

If you have not told HMRC you need to send a return

When you cannot use the service

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Help us improve GOV.UK

Register for and file your Self Assessment tax return

File your tax return online

If you’re filing online for the first time

Sign in to file your tax return

If you have not told HMRC you need to send a return

When you cannot use the service

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