How to Switch from Self Assessment to MTD for Property Income

Making Tax Digital for Income Tax is no longer a future reform to plan around. It is live. From 6 April 2026, landlords whose qualifying income is over £50,000 must keep digital records and report their property income through compatible software in four quarterly updates plus a year-end submission, instead of one annual set of SA105 property pages. The threshold falls to £30,000 from 6 April 2027 and £20,000 from 6 April 2028, so most active landlords will be brought in within three years.

This guide is the one-time switch-over project: how you move from where you are now to filing cleanly under MTD. It is not the side-by-side comparison of the two regimes (see Self Assessment versus the MTD cycle for that), and it is not the recurring quarterly-filing walkthrough you will use every quarter once you are live. It is the sequence that gets you from your current spreadsheet or paper records to a system that satisfies HMRC, run as a project with a clear order: confirm scope, audit records, choose software, sign up, migrate, rehearse, go live.

Are you actually in scope? The gross-income test

The first thing to settle is whether you have to do any of this yet, because the rules turn on a number that catches people out. The mandate is tested on gross qualifying income, your total rental income and any sole-trade turnover before you deduct a single expense, not on your taxable profit.

Mandated from	Gross qualifying income over	Tested against
6 April 2026	£50,000	your 2024/25 Self Assessment return
6 April 2027	£30,000	your 2025/26 return
6 April 2028	£20,000	your 2026/27 return

Because the test is on gross, a high-rent, low-profit landlord is caught even when the net profit looks modest. A few worked examples make the point:

• A landlord with £52,000 of gross rent and £40,000 of allowable costs (net profit £12,000) is in scope from April 2026. The £50,000 line is crossed on the gross figure, not the £12,000 profit.
• A landlord running a £30,000 sole-trade business alongside £25,000 of gross rent is in scope, because the two streams are aggregated to £55,000 for the threshold test.
• A landlord with £40,000 of gross rent and nothing else is not yet in scope in April 2026, but would be drawn in by the £30,000 line from April 2027.

Joint owners test their own share of the gross rent, not the property's total, so one spouse can be mandated while the other is not, and a Form 17 election that splits the income unevenly can bring the larger-share owner in first. If your numbers sit near the line, the gross-versus-net distinction is the single most important thing to get right; our note on the qualifying-income test, gross versus net works through the edge cases, and the April 2026 deadline guide covers who is affected and by when.

Who is not switching: the scope carve-outs

Just as useful as knowing you are in is knowing you are out, because the older advice circulating online frightens landlords who are nowhere near the mandate. Several groups are not switching in April 2026:

• Limited companies are outside MTD for Income Tax entirely. They file annual company tax returns under separate digital rules. If you hold property through a company, none of this applies to that company. If you are weighing incorporation, that is a different decision with its own Capital Gains Tax and Stamp Duty cost; our buy-to-let limited company guide sets out the trade-offs.
• General partnerships and LLPs are deferred to a date still to be confirmed. A partner with separate personal rental or sole-trade income above the threshold is in scope through that other income, but the partnership itself is not mandated yet.
• Trustees are outside MTD for Income Tax. Trust property income continues to be reported through the SA900 trust return as now.
• Pension-held property is separate. Commercial property inside a SIPP or SSAS is taxed within the scheme and reported by the pension trustee, not through your personal MTD cycle. If you hold property both personally and inside a pension, do not combine the two for the threshold test; the pension rental is not your income for that purpose.

What the switch actually changes

At a high level, the move replaces a single annual reporting event with a rhythm of digital submissions. Today you file SA105 property pages once a year. Under MTD you send four quarterly updates of cumulative income and expenses, then close the year with a single year-end obligation: the Final Declaration, where you finalise the property business figures, claim any reliefs and confirm your overall tax position across every income source. The quarterly updates are running totals and not the final word; the Final Declaration is what actually replaces the old annual SA105 reporting. For the full before-and-after, the comparison guide sets the two cycles side by side.

Step 1: Audit your current records

Before you look at software, work out what you already have in a usable form, because that determines how much migration work is ahead. The test is simple: is the record digital and traceable to a source?

• Counts as a digital record: receipt photographs captured by an app with a date stamp, bank-feed extracts pulled by API or CSV, entries already sitting in accounting software, and categorised spreadsheet cells.
• Does not count: shoeboxed paper receipts (which must be digitised), loose photographs with no software audit trail, and figures reconstructed from memory.

The other rule to understand at this stage is the digital link. Once data is in your system, it has to move between software and spreadsheets without manual re-keying: cell references, linked tables, API extracts and scripted imports are fine; copy-paste and re-typing are not. Treat this step as a stock-take, listing each property's income and expense records and flagging what is paper-only, so the migration later is a known quantity rather than a surprise. Our guide to digital record-keeping requirements goes deeper on what HMRC will and will not accept.

Step 2: Choose compatible software

Your software has to do three things: keep your records digitally, submit quarterly updates and file the Final Declaration. Anything that cannot do all three is not a complete MTD solution, however good it is at bookkeeping.

Rather than chase brand names, use HMRC's own compatible-software finder, which is kept current as products are recognised and de-listed. There are two broad routes: full record-creating software that links your bank and captures receipts, and bridging software that connects an existing spreadsheet to HMRC's systems. The spreadsheet-plus-bridging route is genuinely allowed, provided the bridging tool is on the HMRC list and the data flows through a digital link, so spreadsheet-confident landlords do not have to abandon their working method wholesale. For a structured look at the options, see our MTD software options compared. Choose before you sign up, because you link the software to your account during the sign-up step.

Step 3: Sign up with HMRC

Signing up is a discrete step, and it comes after you have chosen software, not before. You register for Making Tax Digital for Income Tax through your existing Government Gateway account, confirm your details and Unique Taxpayer Reference, and connect your chosen software during the process so the two are linked from the start.

Two points are worth holding onto. First, the obligation is yours whether or not HMRC writes to you; the letters are an outreach exercise, not the trigger. If you have had a letter from HMRC about MTD, treat it as a prompt to check the gross test yourself rather than as the start of the clock. Second, keep this step in proportion: it is one stage in the wider project, and the granular screen-by-screen walkthrough lives in our dedicated register for MTD step-by-step guide. The job in your migration plan is simply to slot sign-up in after software choice and before you migrate live data.

Step 3a: If your accountant files for you

If an accountant will handle your MTD filing, the route is the Agent Services Account (ASA), which is the mandatory agent channel for MTD for Income Tax. The flow is straightforward: your accountant generates an authorisation request through their ASA, you receive a link, and you approve them through your own Government Gateway login for MTD filing specifically.

Two details trip people up. Joint owners must each authorise the agent separately; there is no rule that authorising for one spouse covers the other. And authorisations do not transfer if you change accountant, so a new adviser has to request fresh authorisation and you should revoke the old one. The full mechanics are in our Agent Services Account authorisation walkthrough.

Step 4: Migrate your data

This is the step that takes real time, especially across a portfolio. Migration is about getting your starting position and your history into the new software in a shape that the quarterly updates can use. In practice that means three things.

• Opening balances and history. Bring in the income and expenses for the current part-year up to your start date, plus enough history to give continuity. Portfolio landlords should do this property by property rather than as one undifferentiated lump.
• Categorise into the SA105 headings. Map everything into the standard expense categories (gross rent, agent fees, repairs, insurance, council tax, finance costs, other) so each quarterly-update line populates cleanly. Software that mirrors these categories saves rework later.
• Report gross, not net. The most common migration error is entering rent net of letting-agent fees as if it were gross income. Always record the gross rent collected and the agent commission separately as an expense. Netting them off both understates your income for the threshold test and hides a deductible cost.

Where Section 24 affects you, this is also the point to make sure finance costs are captured cleanly, because the basic-rate tax reducer is calculated from them at the year end; our Section 24 guide explains how the restriction works. Section 24 still applies in full inside MTD; the digital cycle changes how you report, not how the relief is computed.

Step 5: Run a parallel dress rehearsal

The cheapest insurance in the whole project is a practice quarter. Keep your existing method running in the run-up to your start date and, alongside it, record a full quarter in the new software and walk through producing a quarterly update without filing it. You are looking for the gaps: a bank feed that misses a managing-agent payment, an expense category that does not map, a property whose opening balance does not reconcile.

What good looks like before April is dull: the parallel quarter reconciles to your existing records, the update produces sensible figures, and nothing about the software surprises you. If the rehearsal throws up problems, you have found them on a quarter that does not count, which is exactly the point.

Go live and your first year on MTD

Once you are mandated, the quarterly cycle runs on fixed dates. For the standard tax-year quarters the deadlines are:

Update period	Submission deadline
6 April to 5 July	7 August
6 July to 5 October	7 November
6 October to 5 January	7 February
6 January to 5 April	7 May
Final Declaration	31 January following the tax year end

The quarterly updates are cumulative running totals, not your final figures, so an estimate that needs refining later is not a problem; you correct it in a later update or at the year end. The year is then closed by the Final Declaration, where you finalise the property business, claim reliefs and confirm your whole position. It falls on 31 January, the same date the old return used. From go-live onward you are into the recurring mechanics, which our quarterly reporting walkthrough covers in detail.

It helps to see the timeline on a real shape. Take an anonymised single landlord with around £60,000 of gross rent across three properties, currently on spreadsheets. A sensible run-up is: records audit early in the run-up year, software choice and HMRC sign-up in the middle, data migration of opening balances and the part-year next, then a parallel dress-rehearsal quarter before 6 April. Come go-live, the first real quarterly update covering 6 April to 5 July is due by 7 August, the three further updates follow on 7 November, 7 February and 7 May, and the Final Declaration lands the following 31 January. No step is heavy on its own; the value is in doing them in order and not leaving migration to the last fortnight.

Penalties if you slip: the real regime

It is worth being precise here, because older guides quote figures that simply are not the law. There is no £200 penalty for every late quarterly update, and there is no separate £400 fixed penalty for record-keeping. The actual regime has two distinct parts.

Late submission is points-based. You receive one penalty point for each missed quarterly update, and a £200 fixed penalty applies only once you reach the four-point threshold for quarterly filers (a further £200 then applies for each subsequent default while you remain at the threshold). Points do not vanish on their own: they reset only after a clean run of a 12-month compliance period and all submissions due in the preceding 24 months having been made. This sits under Schedule 24 to the Finance Act 2021, which is distinct from the older Schedule 24 to the Finance Act 2007 that deals with inaccuracy penalties.

Late payment is separate and faster than the old rules. For MTD for Income Tax from 6 April 2026, the accelerated schedule that took effect on 1 April 2025 under penalty-reform legislation applies: 3% of the unpaid tax once it is 15 days overdue, a further 3% once it is 30 days overdue, then 10% per annum from day 31. These triggers are sharper than the legacy equivalents, so paying on time matters more than it used to. Plan your cash flow around the payment dates as carefully as the filing dates.

If your income later falls: the exit route, and getting help

MTD is not necessarily permanent. If your qualifying income stays below the threshold for three consecutive tax years, you can notify HMRC and exit back to the standard Self Assessment cycle, re-entering only if your income climbs above the line again. Voluntary participants who opted in early can step back out on the same basis. Our note on exiting MTD if your income falls covers the three-year test in full.

Run well, the switch is a one-off project that pays off in clearer numbers through the year. Landlords we work with most often stumble on the same two things: leaving data migration too late, and assuming the HMRC letter is the trigger rather than the gross-income test. Get the order right, rehearse a quarter, and the first real filing is a repeat of something you have already done. MTD is one part of staying compliant; the wider picture, including Capital Gains Tax on disposals and ongoing deduction planning, is covered in our complete property investment tax guide. If you would rather not run the project yourself, the enquiry form on this page is the place to start.