Making Tax Digital for Income Tax (MTD for ITSA) became mandatory on 6 April 2026 for anyone with qualifying income over £50,000, and the rule applies to two groups at once: the self-employed, and landlords. Most of the commentary since April has focused on sole traders, because there are more of them and the "one annual return becomes four quarterly updates" story is simple to tell. Landlords got the same headline change, but underneath it is a set of complications that don't have an equivalent in the sole-trader world, and that accountants with a meaningful buy-to-let book are already running into.
This post looks specifically at what MTD for ITSA requires of landlords, why jointly-owned property makes the threshold calculation harder than it is for a sole trader, and what that means for the accounting firms serving them.
The Same Rollout, a Different Population
The threshold schedule is shared across both groups. Qualifying income above £50,000 (assessed on the 2024/25 tax year) brought landlords and the self-employed into MTD for ITSA from 6 April 2026. The threshold drops to £30,000 from April 2027, and to £20,000 from April 2028, pulling in a much larger share of both populations over the next two years.
"Qualifying income" for this purpose combines gross income from self-employment and gross rental income from property, before expenses are deducted. Someone with £35,000 in sole-trader income and £20,000 in rental income is over the £50,000 threshold even though neither figure alone would trigger it. Employment income (PAYE), pensions, dividends, and most investment income are excluded, and capital gains from selling a property don't count toward the threshold either, only the rental income itself.
The population affected is large. HMRC data published in August 2026 recorded 2.85 million individuals declaring rental income in the 2024/25 tax year, and the English Private Landlord Survey found 45% of landlords own just a single rental property. That single-property landlord, someone with one buy-to-let alongside a main job or a small business, is exactly the client who has never had to think about quarterly digital reporting before and now has to.
Where Landlords Get More Complicated Than Sole Traders
A sole trader's qualifying income is their own. A landlord's often isn't, and that's the structural difference that makes this segment harder to manage.
Jointly-owned property splits the threshold, not just the income. When a property is co-owned, whether by spouses, civil partners, or business partners, each owner assesses their own qualifying income independently, based on their share of the gross rent, not the property's total income. Two co-owners splitting a property 75/25 have different qualifying incomes on the same asset, and can cross the MTD threshold in different tax years. For married couples and civil partners specifically, rental income defaults to an even 50/50 split for tax purposes unless a Form 17 election has been filed to declare a different beneficial ownership split, which means the accountant needs to know not just who owns what, but whether that election exists on file.
One owner can be in MTD while the other isn't. Because each joint owner is tested separately, it's entirely possible for one spouse to be required to file quarterly digital updates while the co-owner of the same property stays on the old annual Self Assessment process, at least until the co-owner's own qualifying income crosses a threshold in a later year. That's a scenario with no direct sole-trader equivalent, since a sole-trader business isn't typically split between two people's individual tax positions in the same way.
The records live in one place but get reported by more than one person. Property income and expenses for a jointly-held portfolio are usually kept as a single set of records, one bank account, one set of invoices for repairs and management fees, but MTD requires each owner to extract and report their own proportional share on their own schedule. That means the accountant (or whoever historically kept the records for the household) now has to make the same underlying data available more frequently, and split correctly, for more than one taxpayer.
Combined income means a landlord can be dragged into MTD by a side business, or vice versa. A landlord with £40,000 in rental income and a £15,000 freelance side income is over the £50,000 combined threshold, even though neither activity alone would be. Firms need to check total qualifying income across everything a client does, not just review the property income in isolation, to know whether a given landlord client is actually in scope.
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Why This Lands Harder on Smaller Firms
The firms most exposed here are the ones with a broad base of small, individual landlord clients rather than a handful of large property businesses. A single-property landlord renting out one flat while working a full-time job is unlikely to have ever kept digital, MTD-compatible records, and is unlikely to understand why a joint-ownership split matters for a tax rule they only heard about this year. That client will ask basic questions repeatedly: which quarter am I actually required to report from, does my share change if my spouse's income changes, why is my sibling co-owner not filing quarterly when I am.
Answering those questions correctly requires the firm to actually track, per client, per property: the ownership split, whether a Form 17 election is on file, each owner's individual qualifying income, and which quarterly deadline applies to which taxpayer. Doing that from memory or from scattered email threads is where firms start making the kind of small, avoidable errors, wrong split applied, wrong owner assumed to be in scope, that are expensive to unwind with HMRC after the fact.
What a Structured Process Looks Like for a Landlord Book
The firms managing this well are treating each landlord client's MTD status as a piece of structured data that needs to be tracked and kept current, not something re-derived from memory every quarter. That means a clear record, visible to the client as well as the firm, of what that specific client (not just the property) needs to submit and when, a place to collect the underlying documents (statements, invoices, management fees) without relying on one person's inbox, and reminders that go out ahead of each of the four deadlines rather than after one has already been missed.
That structure matters even more for joint owners than for a single landlord, because the firm needs both co-owners to understand that they may be on different schedules, submitting different figures, from the same underlying property. A branded client workspace that gives each client visibility into their own specific requirements, rather than a generic "landlord MTD" reminder blasted to the whole book, is what prevents the kind of confusion that turns into missed deadlines or duplicate, conflicting submissions from co-owners.
Osuria brings client communication, document collection, and scheduled deadline reminders together in one secure, branded workspace, built to handle exactly this kind of per-client, deadline-driven complexity rather than treating every client as though they file on the same schedule for the same reasons.
The Threshold Is Only Going to Widen This
At £50,000, MTD for ITSA already covers 2.85 million landlords' worth of qualifying income calculations, a meaningful share of them jointly held. When the threshold drops to £30,000 in April 2027 and £20,000 in April 2028, a much larger slice of the UK's landlord population, including many of the 45% who own just a single property, will be pulled into a regime that was never designed around a single tax return a year.
Firms that build the tracking and communication structure for their landlord clients now, before the next threshold drop forces the rest of the book in, will be managing a predictable, per-client process. Firms that keep handling it ad hoc will be re-solving the same joint-ownership confusion for a growing number of clients every April.
If your firm's landlord clients are generating more back-and-forth about who reports what and when than they used to generate in a full year, it's worth seeing what a purpose-built, branded client workspace looks like in practice. Explore the Digital Workspace or start using Osuria to see how a structured, centralised process handles a client base where the same property can mean two different filing obligations.