Do you still file a Self Assessment under Making Tax Digital?

The short answer: Self Assessment is replaced, not abolished

If you are a sole trader or landlord who has been brought into Making Tax Digital for Income Tax (MTD for IT), you no longer file a traditional Self Assessment tax return. Instead, you submit quarterly updates through MTD-compatible software, then complete a final declaration at the end of the tax year. The final declaration does the same job as the old return — it tells HMRC your total income, your allowable expenses, any other income sources, and it calculates your tax bill — but it sits inside the MTD system rather than arriving as a standalone SA100 form.

So the question is not quite "do I still do Self Assessment?" but rather "what has replaced it, and is it actually different in practice?" The answer to that second question is: yes, meaningfully different, and this page explains exactly how.

Who is affected right now?

MTD for Income Tax became mandatory from 6 April 2026 for sole traders and landlords whose qualifying income exceeds £50,000 in a tax year. HMRC defines qualifying income as the gross turnover from self-employment plus gross property income — before any expenses are deducted. If you crossed that threshold in 2024–25 (the year whose figures HMRC used to assess eligibility for the 2026–27 mandatory start), you are in scope.

HMRC has also been automatically enrolling people who met the threshold but had not voluntarily signed up themselves. If you received a notice from HMRC confirming you have been signed up, you are already inside the MTD regime even if you took no action yourself.

People with qualifying income between £30,000 and £50,000 are expected to join from April 2027, and those between £20,000 and £30,000 from April 2028, though those dates remain subject to legislation. Partnerships are not yet in scope. If your qualifying income is below £50,000 today, you are still filing traditional Self Assessment returns for now.

What the quarterly update actually is — and what it is not

A common source of confusion is the word "quarterly." People assume they are paying tax four times a year or submitting something equivalent to four mini tax returns. Neither is correct.

A quarterly update is a summary of your business income and expenses for that three-month period. It is not a tax calculation, and it does not trigger a payment. Its purpose is to give HMRC a running picture of your trading activity so that, at year end, the final declaration process is simpler. Think of it as a bookkeeping submission rather than a tax submission.

The four quarterly periods and their filing deadlines for the 2026–27 tax year are:

As of today, 15 October 2026, the Q2 deadline of 7 November 2026 is the next one approaching. If you have not yet submitted your Q1 update (deadline 7 August 2026), you should do so as soon as possible — HMRC's penalty regime for late quarterly updates is still being phased in, but accumulating missed submissions is not a position you want to be in when penalties do bite.

The final declaration: this is the part that replaces your tax return

At the end of the tax year, after the fourth quarterly update has been submitted, you complete a final declaration (previously called an End of Period Statement combined with a crystallisation submission — HMRC simplified the terminology). This is the step that locks in your tax position for the year.

The final declaration is where you:

• Confirm or correct the income and expense figures from your quarterly updates
• Add any income that does not come through MTD — for example, employment income, savings interest, dividends, capital gains, or pension income
• Claim any reliefs and allowances not already captured, such as the Marriage Allowance, Gift Aid, or pension contributions
• Confirm your National Insurance position

Once you submit it, HMRC issues a final tax calculation and the amount becomes due. The payment deadlines remain the same as under Self Assessment: the balancing payment for 2026–27 is due by 31 January 2028, with payments on account for 2027–28 also due on 31 January 2028 and 31 July 2028 if applicable.

The final declaration must be submitted by 31 January following the end of the tax year — the same deadline as the old Self Assessment return. For 2026–27, that means 31 January 2028.

A worked example: Rachel the freelance graphic designer

Rachel is a freelance graphic designer working through self-employment. Her gross turnover in 2024–25 was £67,000, which put her above the £50,000 threshold. She was automatically enrolled by HMRC and is now in MTD for the 2026–27 tax year.

During Q2 (6 July to 5 October 2026), Rachel earned £14,500 in invoiced income and spent £2,800 on allowable business expenses (software subscriptions, professional indemnity insurance, and home office costs). She submits a quarterly update through her MTD-compatible accounting software showing those two figures. No tax is calculated or paid at this point — it is a data submission only.

By the time Rachel reaches the final declaration in early 2028, her full-year figures are:

• Gross self-employment income: £71,000
• Total allowable expenses: £11,200
• Net profit: £59,800

She also received £1,400 in bank savings interest during the year, which she adds at the final declaration stage because savings income sits outside the MTD quarterly updates. Her total income assessed for tax is therefore £61,200 (before personal allowance).

After deducting the personal allowance of £12,570 (the figure applying from April 2026, frozen at that level under current government policy), her taxable income is £48,630. The final declaration captures all of this. Rachel's tax and Class 4 National Insurance are calculated on that figure. She pays the balance by 31 January 2028.

The key point: Rachel did not file an SA100 form. She filed four quarterly updates and one final declaration. The end result — a tax bill based on her full annual income — is the same. The process is different.

What if you have income that MTD does not cover?

MTD for Income Tax currently covers self-employment income and property income. It does not yet cover:

• Employment income (PAYE)
• Savings and investment income
• Dividends
• Capital gains
• Pension income
• Foreign income

All of these are reported through the final declaration, which has fields for each income type — much like the supplementary pages of the old SA100. So if you are a sole trader who also has a buy-to-let property, employment income from a second job, or significant savings interest, you still declare all of it, just through the final declaration rather than a paper or online SA return.

One important nuance: if your only income sources are employment income and small amounts of savings interest — and you have no self-employment or property income above the threshold — you will not be in MTD at all, and traditional Self Assessment rules apply to you as they always have.

Do you still register for Self Assessment?

If you are new to self-employment and your income exceeds £50,000, you register for MTD for Income Tax directly rather than going through the old Self Assessment registration route. HMRC's MTD sign-up service handles this. If you were already registered for Self Assessment before MTD became mandatory, your existing registration carries over — you do not need to re-register, but you do need to sign up for MTD through compatible software.

People who were not previously in Self Assessment and whose qualifying income is below £50,000 still register for Self Assessment in the traditional way and continue to file SA returns until the lower thresholds come into force.

Penalties: how late submissions are treated

HMRC has introduced a points-based penalty system for MTD submissions. Each missed quarterly update earns a penalty point. Once points reach a threshold (four points for quarterly filers), a £200 penalty is charged, with further £200 penalties for each subsequent missed submission. Points expire after a period of compliance.

Late final declarations are subject to the same penalty regime that applied to late Self Assessment returns: a £100 fixed penalty immediately after the 31 January deadline, with further daily and percentage-based penalties beyond three months. Unpaid tax after 31 January accrues interest at HMRC's late payment rate, which from April 2026 is set at the Bank of England base rate plus 2.5 percentage points.

A side-by-side comparison: old Self Assessment vs MTD

What you need to do right now

If you are a sole trader or landlord with qualifying income above £50,000 and you have not yet set up MTD-compatible software, this is urgent. You cannot submit quarterly updates through HMRC's own website — you must use software that is listed on HMRC's approved software list. Many providers offer free or low-cost tiers for straightforward businesses.

With the Q2 deadline of 7 November 2026 less than a month away, your immediate priorities are:

1. Confirm you have MTD-compatible software connected to your HMRC account
2. Check that your Q1 update (covering 6 April to 5 July 2026) has been submitted — if not, submit it now
3. Gather your income and expense figures for 6 July to 5 October 2026 and submit your Q2 update before 7 November 2026

If you are unsure whether you have been automatically enrolled by HMRC, log into your Personal Tax Account at gov.uk. HMRC will have sent a notice of enrolment if they signed you up automatically.

Next step: See how EasyTax handles Self Assessment.