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Filing Self Assessment Online and Software Options
If you need to file a Self Assessment tax return, you have two main options: HMRC's free online service or commercial software. Both allow you to submit your return digitally, but they suit different needs. This guide explains how each option works and how to choose the right one for your...
If you need to file a Self Assessment tax return, you have two main options: HMRC's free online service or commercial software. Both allow you to submit your return digitally, but they suit different needs. This guide explains how each option works and how to choose the right one for your circumstances.
Who can file online
You can file your Self Assessment tax return online if you:
- Are self-employed
- Receive income from renting out property
- Have other income to report that requires a Self Assessment return
You can file your tax return anytime from 6 April following the end of the tax year, but you must submit it by the deadline to avoid penalties.
Using HMRC's free online service
HMRC provides a free online service that allows you to complete and submit your tax return directly through your Government Gateway or GOV.UK One Login account. This service works well if your tax affairs are straightforward.
What you can do with HMRC's service
Through the online service, you can:
- File your tax return
- View returns you've made before
- Check your details and how much you owe
- Print your tax calculation
- Sign up for paperless notifications
You don't have to complete your return in one session — you can save your progress and return to it later.
Before you start
You'll need:
- Your Unique Taxpayer Reference (UTR) number
- To be registered for Self Assessment
- Sign in details for HMRC online services (either Government Gateway or GOV.UK One Login)
If you're filing for the first time, you must register for Self Assessment before using the service. If you've registered before but didn't file last year, you may need to reactivate your account. Filing without reactivating an existing account can delay your tax return.
When you cannot use HMRC's online service
You cannot use HMRC's free online service if you:
- File a tax return for a partnership
- File for a trust or estate
- Lived abroad as a non-resident
- Need to report multiple 'chargeable event gains' (for example, from life insurance)
- Receive income from a trust, are a Lloyd's underwriter, or are a religious minister
In these situations, you must use commercial software instead.
Using commercial software
Commercial software can be particularly helpful if you have more complex tax affairs or want additional features to help you complete your return accurately.
Benefits of using software
Some commercial Self Assessment software includes a feature that automatically retrieves information from HMRC to help you complete your tax return. This can include:
- PAYE details, such as income from employment and private pensions
- Taxable social security benefits
- National Insurance details if you're self-employed
- Marriage Allowance information
This feature saves you time and reduces the risk of errors by automatically entering information into the relevant sections of your tax return.
What you need to use commercial software
To use commercial software with these features, you need:
- An HMRC online account registered for Self Assessment
- Compatible Self Assessment software (check with your software supplier whether they include the data retrieval feature)
Granting authority to your software
If your software is compatible, it will ask you to grant authority to access data from HMRC on your behalf. This authority lasts for 18 months, but you can check or withdraw your permissions at any time through your HMRC online account.
Choosing compatible software
HMRC publishes a list of commercial software suppliers for Self Assessment. When choosing software, check whether it includes the features you need and whether it's compatible with HMRC's data retrieval service.
Connecting commercial software to HMRC
The way you connect your commercial software to HMRC depends on how you sign in to your HMRC account.
If you sign in using Government Gateway
If you use Government Gateway to sign in to Self Assessment, simply use the same user ID and password in your commercial software to connect it to HMRC when submitting your tax return. Your Government Gateway user ID could be up to 12 characters.
If you sign in using GOV.UK One Login
If you use GOV.UK One Login (where your username is your email address), you'll need to create a separate, unique Government Gateway user ID and password specifically for your commercial software.
This unique Government Gateway user ID and password cannot be used to access services on GOV.UK — it's only for connecting your software to HMRC.
Creating unique Government Gateway details for software
To create your unique Government Gateway credentials:
1. Sign in to your HMRC online account using your GOV.UK One Login
2. If you're in your personal tax account: select 'Profile and settings', then 'Manage' next to 'Sign in details', then 'View' next to 'Commercial software guidance'
3. If you're in your business tax account: select 'Manage account', then 'View or change your business tax account details', then 'Manage your HMRC sign in details', then 'View' next to 'Commercial software guidance'
4. Read the guidance and select 'Create Government Gateway details'
5. Follow the steps until you've created your unique user ID and password — your user ID will be emailed to you
6. Enter these credentials into your commercial software when submitting your Self Assessment tax return
Making Tax Digital for Income Tax
If you use Making Tax Digital for Income Tax, you need to follow a different process to authorise your software. This uses a separate sign-up and authorisation process.
Getting help
If you have problems using the data retrieval feature in commercial software, contact your software supplier or the HMRC Online Services Helpdesk.
If you think the details you've received from HMRC are wrong, contact the HMRC Income Tax Helpline.
Sources
- File your Self Assessment tax return online
- Check how to submit a Self Assessment tax return using commercial software
- Use software to help complete your Self Assessment tax return
This article provides general guidance based on current HMRC rules. For advice specific to your situation, speak to your accountant.
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