Making Tax Digital for Income Tax went live on 6 April 2026. The first update period ran from 6 April to 5 July 2026 and the first submission was due by 7 August 2026 — covered in detail in our note on the first quarterly deadline. This guide is the whole regime rather than one date: who is caught, what an update contains, what it costs to be late, and the setup that turns it into a fifteen-minute job four times a year.
MTD for Income Tax applies to sole traders and landlords by reference to their qualifying income. Qualifying income is your total turnover from self-employment and property before any expenses. It is not your profit, it is not your taxable income, and it is not what reaches your bank account. HMRC takes the figure from a specific tax return:
This is where associates get it wrong. Take an associate whose practice pay statements showed gross earnings of £78,000 in 2024/25, and whose taxable profit after lab charges, indemnity, GDC retention and motoring came to £46,000. The number they think of as their income is well under £50,000. The number that decides MTD is £78,000, so they have been inside the regime since April 2026. Property turnover counts towards the same total, so a let flat can carry someone over on its own — and it is gross rent, not rent after the mortgage.
Just as important, because it saves several groups of dentists a great deal of unnecessary worry:
The update periods are fixed and every one of them starts on 6 April:
Read those dates again: the periods are cumulative, not four separate quarters. Every update restates the position from the start of the tax year. That is the single most useful feature of the design and the one nobody explains — a mistake in June is corrected simply by reporting the right running total in November. There is no amendment to file and nothing to resubmit.
You can elect for calendar quarters instead (1 April to 30 June, and so on) if that matches your bookkeeping better. The deadlines are the same four dates.
Take an illustrative full-time associate, mixed NHS and private, filing standard quarters.
First update, 6 April to 5 July 2026. Gross earnings on the practice pay statements were £24,900. Lab and materials recharged by the practice came to £1,220, and their own costs — indemnity, GDC retention, CPD, motoring and small equipment — came to £1,830. Expenses of £3,050 were reported. Except that the bookkeeping had also picked up £2,100 of superannuation deducted at source and posted it to expenses, so the figure actually filed on 7 August was £5,150.
Second update, 6 April to 5 October 2026. Six months of pay statements now show gross earnings of £51,600, practice deductions for lab and materials of £2,530, and own costs of £3,810 — total expenses of £6,340. Superannuation of £4,600 for the six months is coded to its own account and stays out of that figure entirely.
Filing £51,600 of income and £6,340 of expenses on 7 November corrects the June error automatically. No amendment, no resubmission, no correspondence. That is the practical answer to "what if I get something wrong" — get the next cumulative update right and the earlier one stops mattering.
The superannuation point is worth labouring, because it is the most common error in dental bookkeeping. Contributions deducted by the practice are a pension contribution, not a trading expense; relief comes through your tax return. Post it to expenses and you overstate relief and understate profit — four times a year instead of once. The NHS pension guide covers how those deductions are estimated and why they need reconciling. Note too that income is the gross figure of £51,600, not the net amount paid into the bank: the practice's deductions are your expenses, not a reduction in your income.
After the tax year ends you make a final declaration by 31 January, which replaces the tax return and is where the real work happens — capital allowances, pension relief, superannuation, other income, and every claim and election. Quarterly updates are summaries of trading income and expenses; they are not calculations and they are not returns.
Payment dates are untouched. Your balancing payment and first payment on account remain due 31 January, and the second payment on account remains due 31 July. What genuinely improves is visibility: with records current all year you can see the bill coming rather than meeting it in January, which is what turns the monthly set-aside from a guess into a number.
There are no penalty points for late quarterly updates in 2026/27. HMRC is not applying them in the first year of the regime. From 2027/28 the points system operates: one point per missed submission deadline, a £200 penalty at 4 points, and a further £200 for every miss after that. Points below the threshold fall away automatically 24 months after the missed deadline; once you are at the threshold you have to file on time for 12 months and clear any outstanding submissions from the previous 24 months.
Your return and your payments are a separate matter and their penalties apply now. Late payment costs 3% of the tax outstanding at day 15, a further 3% of what is outstanding at day 30, then 10% a year accruing daily from day 31 — on top of late payment interest, currently 7.75%, set at the Bank of England base rate plus 4 percentage points since 9 January 2026. The base rate was held at 3.75% on 30 July 2026.
Exemption is available on grounds of digital exclusion — age, disability, location or religious observance that makes it not reasonably practicable to use compatible software. It is applied for individually, and it is decided on your personal circumstances rather than granted by category. An exempt dentist still files a self assessment return in the ordinary way. Applications can be made by you, by your agent, or by a friend or family member with your authority. Being busy, or preferring a spreadsheet, is not a ground.
An associate's finances are cleaner than almost any other small business: one main income stream arriving as a monthly pay statement, a modest set of recurring costs, no stock and no sales ledger. Four things do all the work, and they are worth doing this week rather than the week before a deadline:
Do the fastest honest version rather than waiting until the records are perfect. Pull the pay statements for the period, total the gross earnings and the practice deductions, add your own costs from the bank, and file. The cumulative design means a rough-but-reasonable update gets tidied in the next one, and there is no penalty for a late update this tax year. Then fix the system properly, once. Migrating mid-year is far easier than reconstructing three missed quarters next spring.
Deadlines coming up, rule changes that affect dentists, and one number worth checking — once a month, no spam.
If your qualifying income was over £50,000, yes — from 6 April 2026. The catch is what qualifying income means: total turnover from self-employment and property before any expenses, taken from your 2024/25 tax return. It is the gross figure on your practice pay statements, not your profit and not what reached your bank. An associate grossing £78,000 who takes home £46,000 after lab charges, indemnity, GDC fees and motoring is inside the regime. Gross rental income counts towards the same total. The threshold falls to £30,000 from 6 April 2027 and £20,000 from 6 April 2028, so part-time associates follow shortly after.
Not for the company's profits. MTD for Income Tax applies to sole traders and landlords, and a company reports through corporation tax instead, so salary and dividends you draw from your own company do not count as qualifying income. You can therefore have a large income and no quarterly updates at all. Two things still catch incorporated principals: any income you keep outside the company as a sole trader, and rental property, both of which count towards the £50,000 test in the ordinary way. Practices held in partnership are also outside this phase of MTD.
For 2026/27, nothing financial — HMRC is not issuing penalty points for late quarterly updates in the first year of the regime, so a missed deadline this year is a process failure rather than a fine. From 2027/28 it is one point per missed deadline, a £200 penalty once you reach four points, and a further £200 for every miss after that. Because the updates are cumulative, the practical fix is to file the next one on time: it covers everything from 6 April anyway. Your return and payment deadlines are unaffected and their penalties apply as normal.
Exemption exists on digital exclusion grounds — where age, disability, location or religious observance makes it not reasonably practicable for you to keep digital records and file from compatible software. You apply for it individually and HMRC decides on your personal circumstances, so it is not granted by category or by profession. You, your agent, or a friend or family member acting with your authority can make the application. Preferring a spreadsheet, being short of time or finding the software irritating are not grounds. An exempt dentist still files a self assessment return in the ordinary way.
Your business income and expenses, recorded in MTD-compatible software as they arise rather than reconstructed after year end. For an associate that means the monthly practice pay statement broken out properly — gross earnings, lab and materials deducted, and superannuation coded separately outside trading expenses — plus your own costs captured through a bank feed and a receipts app. You do not have to store paper receipts digitally for MTD, though doing so makes life easier. Reliefs, capital allowances and pension contributions belong in the final declaration, not the quarterly updates.
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