Making Tax Digital – how does it interact with self-assessment?

It can be confusing when you first join MTD for income tax. You will still need to file your self-assessment tax return for the previous tax year. Therefore, there will be at least one tax year where you need to file: 

• a self-assessment tax return for the previous year, and  
• MTD quarterly updates for the current year. 

See our guide here for an example of the key dates if you join MTD for income tax in 2026.  

We answer other questions we have received about self-assessment and MTD for income tax below. 

Can you not do your tax return early anymore? Do you have to wait until you've delivered all four quarterly updates? 

Once you are within MTD for income tax, you can still file your MTD end of year tax return before the 31st January deadline. Your final quarterly update is due by 7th May following the tax year end. Once that fourth quarterly update is sent, you can file your end of year tax return through your MTD software. 

If it is your first year within MTD for income tax, you will still need to file your self-assessment tax return for the previous year. This can be filed before the 31st January deadline too. 

Will self-assessment still apply if I don't meet the £50,000 threshold? 

Yes – if you don’t meet the £50,000 qualifying income threshold for 2026/27, you are correct and you will stay within the self-assessment regime. Do check your qualifying income again when you file your 2025/26 tax return as if it is over £30,000, you will need to join MTD for income tax for the 2027/28 tax year. 

Can you elect to start the MTD for income tax process even if you don't meet the qualifying income threshold? 

Yes, you can join MTD for income tax on a voluntary basis before it is mandatory. If you sign up part way through a tax year you will need to catch up on any quarterly updates you have missed. You will need to agree to the MTD for income tax penalty regime if you sign up as a volunteer. 

If I don’t join MTD for income tax, do I just do my self-assessment tax return as usual? 

If you meet the qualifying income threshold for the tax year (£50,000 per your 2024/25 tax return for 2026/27), then unless you successfully claim an exemption, joining MTD for income tax is mandatory and you cannot choose to stay within self-assessment instead. 

However, if you do not meet the qualifying income threshold, you should continue reporting your taxable income under self-assessment.  

 

First published 6 Jul 2026

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This article is intended to inform rather than advise and is based on legislation and practice at the time. Taxpayer’s circumstances do vary and if you feel that the information provided is beneficial it is important that you contact us before implementation. If you take, or do not take action as a result of reading this article, before receiving our written endorsement, we will accept no responsibility for any financial loss incurred.

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