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How to register for Self Assessment 

  • 3 min read
  • Last updated 28 Mar 2024

Want to know how you can register for Self Assessment? Well luckily, you’re not the only one! That’s why we’ve put together a short and simple guide that will help you breeze through the Self Assessment registration process!

Firstly, what is a Self Assessment?

Self Assessment is the method used to submit personal tax returns to HMRC in the UK. It details all your income and expenses – HMRC uses this information to calculate how much tax you owe.

So, how do you register for Self Assessment?

We know we said we’d make it short and simple, but technically there’s no one shoe fits all when it comes to registering for Self Assessment. Ie. If you earn over 100k, the process will be slightly different from someone who is self-employed. 

A little confused? Ok, let’s break it down:

If you’re self employed, and haven’t filed a tax return before:

  • Register for Self Assessment through your business tax account: You’ll need your government gateway ID to hand – chances are you’ve forgotten this, right? No worries, if you have a look in your email, it should be there!
  • In about 10 days, your UTR number should come through the letterbox: Be sure to keep this safe otherwise it will be a pain when it’s time to file your tax return!

What if I’ve registered for Self Assessment before?

If you’ve registered in the past and filed your tax return online but didn’t file one last year:

  • You can re-register online using a CWF1 form
  • You’ll need your UTR for this (you should’ve received this when you first registered)

If you registered but didn’t use the online services to file your tax return:

  • Sign in to your business tax account (or create one)
  • Add Self Assessment
  • You’ll need your Government Gateway ID and UTR number

Whether you’ve done a tax return before or not, you can register via post by:

  • Filling in this online form
  • Printing it off 
  • Sending it to HMRC – easy peasy! 

You can fill out a SA1 form if you fall into one of these categories:

  • You’ve become a company director
  • Have capital gains tax to pay
  • Have taxable foreign income of more than £300 per annum
  • Receive income from land and property in the UK
  • Have any uncollected income tax

You can fill this form out online or print and send via post – whatever is easiest for you!

What information do I need to register for Self Assessment?

Good question! HMRC will want to know:

  • Your full name
  • Your national insurance number
  • Current address (and when you moved in)
  • Your date of birth 
  • Your phone number and email address

How long does it take to register for SA?

It can take around 4 weeks to complete the Self Assessment registration process – so our advice is to start asap!

⚠️ The deadline is 5th October after the end of the tax year. ⚠️

Take a look at this video that HMRC put together that gives an overview on how to register.

I missed the deadline to register for Self Assessment, now what?

Yikes! This can be a pretty awkward situation and could mean you end up missing the deadline to file your taxes, which you definitely don’t want to do!

In this case we’d recommend getting in touch with HMRC asap using the Self Assessment helpline: 0300 200 3310.

If you’ve already registered in the past, then as long as you have your UTR number, you can file your return and pay your tax, and HMRC won’t penalise you.

Never, (and we mean NEVER) ignore the situation and hope it will magically disappear as this could land you a fine from HMRC – they can be pretty brutal at times!

Don’t panic! 🙅

Our accredited accountants will handle all the boring paperwork for you! Your tax return can be sorted in as little as 48 hours – find out more here.

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