What Making Tax Digital for Income Tax Actually Is
Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) is the government's programme to move sole traders and landlords away from a single annual Self Assessment return and onto a system of quarterly digital submissions. The legal foundation sits in the Finance (No. 2) Act 2017, which gave HMRC the power to mandate digital record-keeping and electronic reporting for income tax. Secondary legislation — specifically the Income Tax (Digital Requirements) Regulations 2021 (SI 2021/1076) — sets out the precise technical obligations: what software must do, what records must be kept digitally, and the format of quarterly updates.
The key practical shift is this. Under the current system you pull together a year's worth of income and expenses every January and submit one return. Under MTD for ITSA you submit four quarterly updates during the year, each one drawn from your digital records, followed by a final declaration that reconciles everything. HMRC describes the quarterly updates as 'cumulative' — meaning each update reports totals from the start of the tax year to the end of that quarter, not just the three months in isolation. That distinction matters for how your bookkeeping software displays figures.
The policy intent is to reduce the tax gap caused by errors and under-reporting. HMRC's own estimates put avoidable errors in Self Assessment at around £5 billion per year. Whether the policy achieves that aim is debatable, but the obligation itself is not optional once the income threshold is met.
Who Is Affected and from When
The rollout is staged by income level. From 6 April 2026, sole traders and landlords with gross trading income above £50,000 must comply. From 6 April 2027, the threshold drops to £30,000. A further extension to £20,000 has been announced for April 2028, though that date remains subject to parliamentary confirmation at the time of writing.
Gross trading income means your total turnover before any expenses. If you are a sole-trader electrician turning over £52,000 but your net profit after materials and van costs is only £28,000, you still fall into the April 2026 cohort. The threshold is not profit — it is receipts. If you have multiple income sources, HMRC aggregates them: a plumber earning £35,000 from plumbing and £18,000 from a rental property would have combined qualifying income of £53,000 and would be caught from April 2026.
Certain categories remain exempt from MTD for ITSA even above the threshold. These include individuals whose tax affairs are managed by a trustee, those in partnerships (though a separate MTD for partnerships is planned for a later date), and those with a religious objection to using computers — a narrow exemption requiring a formal application to HMRC. General Partnerships are currently excluded until at least 2025-26, so if you run your trade through a partnership rather than as a sole trader, check the position separately.
- •April 2026: gross income above £50,000
- •April 2027: gross income above £30,000
- •April 2028 (planned): gross income above £20,000
- •Threshold is total receipts, not profit
- •Multiple income sources are aggregated by HMRC
The Quarterly Submission Cycle in Plain Terms
Under MTD for ITSA your tax year still runs 6 April to 5 April, but you now report in four quarters. The quarters and their submission deadlines are fixed. Quarter 1 covers 6 April to 5 July, with the update due by 7 August. Quarter 2 covers 6 July to 5 October, due by 7 November. Quarter 3 covers 6 October to 5 January, due by 7 February. Quarter 4 covers 6 January to 5 April, due by 7 May. The final declaration — which replaces the old Self Assessment return — is due by 31 January following the end of the tax year, the same deadline as today.
Each quarterly update does not replace the final settlement of your tax bill. The update tells HMRC your cumulative income and expenses to that point in the year. HMRC will show you a running estimate of the tax you might owe. The actual liability is only crystallised through the final declaration. Think of the quarterly updates as a running tally, and the final declaration as the closing of the account. You still pay your tax in two payments on account by 31 January and 31 July, as now.
The quarterly updates must be submitted through HMRC-recognised software. HMRC does not provide a free portal equivalent to the current online Self Assessment form. You must use commercial software that has been through HMRC's API recognition process. A spreadsheet on its own does not qualify — you need bridging software or a fully compatible application. HMRC publishes a list of recognised software products on GOV.UK, and it is worth checking that list before committing to any tool.
- •Q1 (6 Apr to 5 Jul): update due 7 August
- •Q2 (6 Jul to 5 Oct): update due 7 November
- •Q3 (6 Oct to 5 Jan): update due 7 February
- •Q4 (6 Jan to 5 Apr): update due 7 May
- •Final declaration: 31 January as before
- •Payment on account dates unchanged: 31 January and 31 July
Digital Record-Keeping: What You Must Actually Do
Regulation 4 of the Income Tax (Digital Requirements) Regulations 2021 sets out what counts as a 'digital record'. For each transaction you must record the date, the amount, the category of income or expense, and whether it is a business or personal item. HMRC permits you to record transactions in a spreadsheet and use bridging software to push that data to their API, but every entry in the chain from your records to the HMRC submission must be digital. Writing figures in a notebook and then typing them into software once a quarter is not compliant — the original record must itself be captured digitally.
In practice this means photographing or scanning receipts and logging them in your software at or near the time of transaction. For tradespeople the critical records include: income received from customers (whether cash, bank transfer, or cheque), materials purchases, fuel and vehicle costs, tool purchases, subcontractor payments (especially relevant under the Construction Industry Scheme), and any proportion of home costs if you claim a home office. HMRC is not yet requiring digital copies of every receipt — only digital records of each transaction — but keeping digital images is good practice and protects you in an enquiry.
If you use the cash basis for accounting, as most sole traders with turnover under £150,000 currently do, you record income when received and expenses when paid. MTD does not change the accounting basis rules — it changes only the frequency and format of reporting. The cash basis is still available and is likely to remain so for the period following the 2026 start date, though HMRC has consulted on simplifying the rules.
The Construction Industry Scheme and MTD: How They Interact
Many sole-trader tradespeople working under the Construction Industry Scheme (CIS) face a specific complication. Under the Finance Act 2004 and the Income Tax (Construction Industry Scheme) Regulations 2005 (SI 2005/2045), contractors deduct tax at source from your payments — typically 20% if you hold gross payment status, or 30% if you are unregistered. Those deductions are credits against your income tax liability and are currently reconciled through your annual Self Assessment return.
Under MTD for ITSA, those CIS deductions will still need to be reported and reconciled, but the process for doing so within quarterly updates is still being finalised by HMRC. At the time of writing, HMRC has indicated that CIS deductions suffered will be declared in the final declaration rather than in each quarterly update, because the information from contractors may arrive after the quarterly deadline. If you work across multiple contractors, you will need to gather monthly CIS statements from each one and keep them digitally. A sole trader who misses a CIS credit because they lost a contractor's statement could end up overpaying tax — or triggering an unwanted enquiry.
The interaction with CIS gross payment status is worth noting separately. To retain or apply for gross payment status, you must demonstrate a consistent compliance record, which now includes MTD compliance from April 2026. Failing to file quarterly updates on time could jeopardise a gross payment status application or renewal, with a practical financial consequence of 20% being withheld from every payment by contractors.
VAT and MTD: The Position for Tradespeople Already Enrolled
If your turnover exceeds the VAT registration threshold (currently £90,000), you are almost certainly already operating under Making Tax Digital for VAT, which became mandatory for all VAT-registered businesses from April 2022. The digital record-keeping habits you have built for MTD for VAT will transfer directly to MTD for ITSA, but the two regimes are separate. Your VAT records and your income tax records must both be maintained digitally, though a single piece of software can handle both if it is designed to do so.
For tradespeople who use the VAT domestic reverse charge — which applies under VAT Notice 735 to most construction services supplied to other VAT-registered businesses in the supply chain — the bookkeeping treatment requires care. Under reverse charge, you do not charge VAT on qualifying supplies and do not include those supplies in your Box 1 VAT output figure. In your income tax records, the net revenue figure from reverse charge invoices is still your trading income for MTD for ITSA purposes. The reverse charge does not reduce your reportable turnover — it only affects VAT accounting.
Tradespeople close to the £90,000 VAT threshold should be aware that MTD for ITSA quarterly submissions will give HMRC a more current view of your turnover throughout the year. If your income crosses the VAT threshold mid-year and you are late registering, HMRC's real-time data from MTD updates will make that gap more visible than it was under annual Self Assessment.
Penalties for Non-Compliance: The Real Figures
HMRC has confirmed that the new points-based penalty system introduced by the Finance Act 2021 will apply to MTD for ITSA from April 2026. This replaces the old fixed automatic penalties for late filing of Self Assessment returns. Under the points-based system, every late quarterly update earns you one penalty point. Once you reach a threshold of points, a financial penalty of £200 is triggered. For quarterly filers the threshold is four points, meaning you can be late four times before the first £200 penalty lands — but those points then accumulate. To have points removed, you must file on time for a continuous period of 12 months and have no outstanding submissions.
The £200 penalty is per penalty threshold reached, not per missed submission. However, if you miss all four quarterly updates in a year and the final declaration, you will accumulate five points, which takes you well past the threshold. Once in the penalty regime you also face late payment penalties: 2% of unpaid tax after 15 days, a further 2% (so 4% total) after 30 days, and then a daily rate of 4% per annum on the remaining balance. For a tradesperson with a £5,000 tax bill unpaid at day 30, the 4% charge adds £200 immediately, growing daily thereafter.
Serious or deliberate failures attract behaviour-based penalties under Schedule 41 of the Finance Act 2008, which remain in force. Deliberate and concealed inaccuracies can attract penalties of up to 100% of the unpaid tax. A sole trader who simply stops submitting quarterly updates and does not engage with HMRC will find that the points-based system escalates quickly, and that HMRC can make a determination of the tax owed — which you then have to challenge and correct at your own cost.
- •Late quarterly update: 1 penalty point
- •4 points reached: £200 financial penalty triggered
- •Points cleared only after 12 consecutive months of on-time filing
- •Unpaid tax after 15 days: 2% surcharge
- •Unpaid tax after 30 days: 4% surcharge (cumulative)
- •Ongoing late payment: 4% per annum daily rate thereafter
- •Deliberate inaccuracies: up to 100% of unpaid tax under Finance Act 2008, Sch 41
Worked Example: A Sole-Trader Plumber in 2026-27
Take Gary, a sole-trader plumber based in Leeds. His gross turnover for 2025-26 was £58,000. He is therefore required to comply with MTD for ITSA from 6 April 2026. He uses a simple cloud-based bookkeeping app that has HMRC API recognition. From April 2026 he logs every invoice raised and every purchase made at the time of the transaction.
By 7 August 2026, Gary submits his Quarter 1 update. His digital records show: income received £14,200, materials £3,100, vehicle costs £1,800, tools £400, insurance £350. His cumulative net profit to 5 July is approximately £8,550. HMRC's system shows Gary a running tax estimate based on that profit — say £1,710 at the basic rate. Gary does not pay anything at this stage; it is an estimate only. He repeats this process for Q2, Q3, and Q4, each time submitting the cumulative figures from 6 April to the end of that quarter.
By 31 January 2027, Gary files his final declaration. His full-year figures are: total income £59,400, total allowable expenses £22,800, net profit £36,600. After his personal allowance of £12,570, his taxable income is £24,030. Tax at 20% is £4,806. National Insurance is calculated separately. Gary has already paid £2,403 on account by 31 January 2026 and a further £2,403 by 31 July 2026, so the balancing payment due on 31 January 2027 is small. Because Gary filed all four quarterly updates and his final declaration on time, he has zero penalty points. If he had missed Q3 and Q4, he would have two points — no penalty yet, but two strikes recorded.
Choosing Software: What to Look For
HMRC does not endorse specific products, but it does maintain a list of software compatible with the MTD for ITSA API on GOV.UK. Before April 2026, check that any software you plan to use appears on that list and supports both quarterly updates and the final declaration — some early products supported only one of these functions. The software must also be capable of maintaining digital records in the format HMRC requires, not just submitting a total figure.
For most sole-trader tradespeople the practical requirements are straightforward: capture income and expenses digitally, categorise them correctly, and push the quarterly cumulative totals to HMRC via the API. Many of the well-known bookkeeping packages already do this. If you currently use a spreadsheet, check whether your software provider offers a bridging tool — a small application that reads your spreadsheet and submits the data digitally. Bridging is permitted under the regulations, but every step in the chain from your spreadsheet cell to HMRC's database must be a digital transfer, not a human re-keying of figures.
Cost is a real consideration for sole traders. Free-tier products exist and may be adequate if your bookkeeping is simple. Paid tiers typically add bank feeds, automated categorisation, and direct submission without manual export steps. If you are already paying an accountant to handle your Self Assessment, discuss with them how the quarterly submission cycle changes their workload and your fee. Some accountants are pricing MTD compliance as an add-on; others are folding it into a fixed monthly retainer.
- •Confirm the software appears on HMRC's recognised product list
- •Check it supports both quarterly updates AND the final declaration
- •Bridging software is permitted but every step must be digital — no manual re-keying
- •Bank feed integration reduces manual entry errors
- •Discuss accountant fee changes before April 2026, not after
Steps to Take Before April 2026
The most common mistake tradespeople make with new compliance requirements is assuming they have time to sort it out later. April 2026 is closer than it looks, particularly if you factor in the time to select software, migrate your existing records, set up bank feeds, and complete a test run before the first live quarterly deadline of 7 August 2026. The practical preparation window is now.
Start by confirming whether your gross income for 2024-25 is above or likely to approach the £50,000 threshold. If you are close, plan on the basis that you will be in scope. Register for MTD for ITSA through your Government Gateway account — HMRC has a sign-up service and recommends registering at least six months before your mandation date. If you use an accountant, authorise them as your agent within the MTD service rather than the general Self Assessment agent authorisation, since the two are separate within HMRC's systems.
Run your chosen software in parallel with your existing record-keeping for at least one quarter before April 2026. This surfaces any gaps in how you categorise expenses, any income streams you had not been capturing correctly, and any CIS deductions that require special treatment. Catching those issues in a dry run is far less painful than discovering them during a live submission that affects your tax liability.
- •Check your 2024-25 gross income against the £50,000 threshold now
- •Sign up through Government Gateway — do not wait until March 2026
- •Authorise your accountant under the MTD agent service specifically
- •Run a parallel trial on your chosen software for at least one full quarter
- •Collect and digitise any paper records going back 6 years (the enquiry window under normal HMRC practice)
- •Confirm your CIS contractor statements are being received and stored digitally
How TradeDoc AI Fits Into Your MTD Preparation
Keeping your customer-facing documents — quotes, invoices, job completion sheets — in good digital order is a sensible first step toward the wider digital record-keeping MTD requires. TradeDoc AI generates compliant trade documents in about two minutes, covers all four main trades in one place, and is free for your first 100 documents a month with no card required at sign-up. If you want your logo on the PDF and one-tap email send direct to the customer, Pro is £15 per month. Visit tradedoc.co.uk to get started.
