Register for and file your Self Assessment tax return

7 mins

Our experts at DSR Tax Refunds know how hard it is to find good, quality information about HMRC’s tax regulations that is easy to understand, and that’s why we have created these handy guides to tell you everything you need to know. Our aim is to make life easier for our clients and that is why we want to share our expertise with you. You can also call our friendly team on 0330 122 9972 – we’re the tax experts you can trust.
What are the benefits of HMRC’s online Self Assessment service?
The easiest way to sort out your taxes these days is online. If you use HMRC’s online Self Assessment service, you can register for Self Assessment as well as fill in and send your Self Assessment tax return.
The online service gives you the ability to register online for Self Assessment and receive your UTR (Unique Taxpayer Reference). Once set up to use the online service, you can then fill in and send your Self Assessment tax return to HMRC. You can also go back to a tax return you have already started but didn’t finish – you don’t have to get all of your financial details entered in one session. It also gives you the ability to check your details with HMRC, view your submitted tax returns and print your tax calculation.
If you have already registered for Self Assessment and you have a UTR but you didn’t send a tax return last year, you will need to register for Self Assessment again but you won’t need a new UTR – the one you have will still be valid.
What if this is the first time you’ve needed to file a tax return?
If this is the first time you have been required to file a tax return, you need to get a few things sorted with HMRC first. Before you can begin to file a Self Assessment tax return, you need a UTR or Unique Taxpayer Reference. A UTR is a 10-digit reference number, unique to you, which allows all of your tax records to be attributed to you – so any tax that you pay through Self Assessment is accredited to you only. You can apply for one online. You will receive your UTR through the post – HMRC don’t allow you to receive it online.
Once you have your UTR, you can enrol for the online Self Assessment service. You will need to create a Government Gateway account if you haven’t already and you will also need an access code to activate the service – this is also sent by post.
You can’t use the online service if any of the following circumstances apply to you. You will be expected to file your tax return via a different method if:

What if HMRC don’t know you need to file a tax return?
If you haven’t told HMRC that you need to file a Self Assessment tax return, the first thing you need to do is register for Self Assessment. There are different ways to do this if your employment status is one of the following:

It can take a while to complete the registration process because you have to receive certain information by post, so make sure you leave enough time to register before you have to file your Self Assessment tax return. HMRC issues penalties for late submission of tax returns and not having registered in time isn’t considered a valid excuse.
How do you register if you are self-employed?
You need to register for Self Assessment as soon as you can once you have started your business or become a self-employed sole trader. HMRC rules state that you must have registered by 5th October in your business’s second tax year or they might fine you for not registering in time. You will be registering for Self Assessment and Class 2 National Insurance.
If you haven’t sent a tax return before, you will need to register online to get your UTR (Unique Taxpayer Reference) – this is a 10-digit reference number, which HMRC will send to you by post. You will also be enrolled in the Self Assessment online service. HMRC will also send you an activation code for your online Self Assessment account through the post – this will take around 10 working days (21 days if you are based abroad). You will need this activation code when you first log into your account. The code is valid for 28 days after which time you will have to reregister to get a new code.   If you don’t receive your activation code or you lose it before you get chance to log into your account, you can get a replacement by signing into your Government Gateway account.
If you don’t want to register online, you can fill in a form on-screen and then print it off and post it to HMRC. You need to have all your information to hand when you start this because, unlike with the online service, you won’t be able to save a partly completed form.
If you have sent a tax return in the past, you will already have a UTR which you will be able to find on any correspondence from HMRC about your past Self Assessment tax returns. If you have previously signed up for the online service, you will still be able to use the same account to file your tax return but if you didn’t send a tax return for the last tax year, you will need to reregister for Self Assessment with HMRC.
How do you register if you’re not self-employed?
There are a number of reasons why you might need to register for Self Assessment – for example, you might be a company director or receive income on top of your PAYE earnings that you need to report to HMRC. If any of the following circumstances apply, you will need to apply for Self Assessment:

To register for Self Assessment if you aren’t self-employed, you need to fill in form SA1  – you can either do this online or fill it in and print it off and send it by post, if you would rather not apply online.
If you have already sent a return in the past, it’s pretty easy to return your new Self Assessment tax return. You use the same UTR that you used for your previous tax returns and you can also use the same online account you previously used too. If you didn’t send a tax return for the last tax year, you will need to reregister for Self Assessment with HMRC
If you haven’t sent a tax return before, you will need to wait for HMRC to send you your UTR (Unique Taxpayer Reference) which will take around 10 working days to arrive. You will need this UTR to enrol for the online Self Assessment service. Once you have enrolled online, you will need to wait for your activation code to arrive by post – this should also take around 10 working days. You will need this activation code to log into your online account for the first time.
How do you register if you are a partner or in a partnership?
If you are a business partner in a business partnership you need to register for Self Assessment. You will be registering for Self Assessment and to pay Class 2 National Insurance contributions. When you register as a partner, you will also need your partnership’s UTR. You will need to use online form SA401 which you can either send online or by printing and sending by post. If you are unable to fill in the form on-screen, there is also the facility to print the form off and fill it in by hand.
If you are the ‘nominated partner’ in the partnership, you also need to register your partnership for Self Assessment. For this, you will need to fill in form SA400 which again, can be sent online or printed and sent by post. As with registering as a business partner, you can also print off a form to fill in by hand and return by post. As the nominated partner, you will then be responsible for returning the Self Assessment tax return for the partnership as well as your own personal Self Assessment tax return.
You can’t use this method of registering for Self Assessment if you are registering a limited liability partnership or one member of the partner is not an individual, for example, if one partner is a company or trust.
How can DSR Tax Refunds help?
We aim to make life as simple as possible for our clients and that includes giving you the information you need to make your taxes (and your life) simpler and less stressful.  Our team of experts at DSR Tax Refunds are always on hand to help our clients and our excellent standing with HMRC means that we can make sure you don’t fall foul of their regulations, while claiming your maximum tax relief. We can even take care of all that paperwork and deal with HMRC on your behalf too. Call our friendly team on 0330 122 9972 – we’re the tax experts you can trust.
This page was last updated on 26/10/2018.

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