HMRC Landlord Disclosures Doubled in 2025/26: The UK Accounting Firm Window

HMRC took more from landlords in 2025/26 than in any year of the campaign

The let property campaign has been running since 2013. It is the oldest disclosure facility HMRC still operates, and for most of its life it has been a quiet corner of the tax system. The 2025/26 reporting year ended that.

Figures obtained from HMRC and published on AccountingWEB by tax investigations specialist Amit Puri show 12,660 let property campaign disclosures in 2025/26, close to double the 6,490 received the year before. Those disclosures carried 42.8m pounds in tax, 26.3m pounds in interest and 2.1m pounds in penalties, for total revenue of 71.2m pounds.

Running alongside the voluntary route, HMRC's own let property compliance activities brought in a further 88.3m pounds in the same year: 61.5m pounds in tax, 15.3m pounds in interest and 11.5m pounds in penalties.

Cumulatively, HMRC has now secured close to 550m pounds from let property work since 2013, across roughly 100,000 disclosures. HMRC's original estimate was that up to 1.5 million landlords had underpaid tax. Whatever you think of that estimate, the arithmetic says this campaign is nowhere near finished.

The number that should shape your advisory offer

Two penalty rates sit inside that data, and the gap between them is the entire commercial argument for this service line.

In 2025/26, penalties on voluntary let property campaign disclosures ran at 4.8% of total revenue secured. Penalties on HMRC's own compliance activities over the same period ran at 18.7%.

That is close to a fourfold difference in penalty exposure, and it is decided almost entirely by who moved first. A landlord who comes forward through the disclosure facility is treated as unprompted. A landlord who waits until HMRC opens a check is prompted, and the behaviour-based penalty regime prices that difference in.

The 2024/25 figures make the same point more sharply: 2.8% on disclosures against 21.2% on compliance activities.

For a firm advising landlords, that is not a technical footnote. It is a quantified reason to act this quarter rather than next year, and it is exactly the kind of specific, checkable number that turns a vague "we can help with your tax" message into an argument a client cannot reasonably ignore.

Why the letters are arriving faster

Three things changed at once.

Data. HMRC cross-matches Land Registry ownership records, letting agent returns and tenancy deposit scheme data. Since 1 January 2024, digital platforms including short-let and booking sites have had to report seller and host income under the UK's platform reporting rules. A landlord with three flats and an occasional holiday let now appears in several datasets that did not previously talk to each other.

Structure. As Puri notes, most let property nudge letters and enquiry correspondence now issue from HMRC's new front-line directorate, volume compliance and support operations. The name is the strategy. This is deliberately industrialised, letter-first compliance rather than case-by-case investigation.

Interest rates. Interest charged on 2025/26 disclosures came to 26.3m pounds against 42.8m pounds of tax, a ratio far above earlier years. Late payment interest has been high and has stayed high, which means the cost of a landlord sitting on an unresolved position compounds every month they delay.

The opportunity: a defined, urgent, high-value engagement

Most practice development ideas fail because the client has no reason to act now. This one has a deadline attached by HMRC. The letters typically set a short response window and often enclose a certificate of tax position, which is a document no landlord should be completing without advice.

The engagement itself is well shaped for a small or mid-sized firm:

- Scoping which tax years are actually in point under the assessment time limits - Reconstructing records where the landlord has none, which is most of them - Computing tax, interest and the correct behaviour category, since careless and deliberate carry very different consequences - Preparing and submitting the disclosure - Handling the follow-up correspondence, including the interest recalculation disputes that practitioners on AccountingWEB describe as routine

That is a defined project fee. What follows it is better: a landlord who has just been through a disclosure is a landlord who will pay for an annual return, capital gains advice on disposals, and help getting ready for Making Tax Digital for income tax. A one-off remediation converts into a recurring relationship more reliably than almost any other entry point in practice.

The opportunity cost: this work is being won on search, not referral

Here is the uncomfortable part. The landlord who opens that brown envelope on a Tuesday evening is frightened, and frightened people search. They type the letter reference into Google. They search for what a certificate of tax position is. They search for whether they can go to prison.

Many of them do not have an accountant at all, because they have been self-filing or not filing. There is no existing adviser to call. The firm that appears in that search wins a client who arrives pre-qualified, urgent and price-insensitive.

Notice who is already occupying that ground. The most authoritative public analysis of the 2025/26 let property data was written by a tax investigations boutique and published on the profession's largest UK title. That is content marketing executed properly, and it works: the specialists get the referrals and the enquiries because they publish, and the general practice down the road that quietly does excellent disclosure work gets nothing, because nobody can find it.

Staying invisible on this topic does not keep the work neutral. It hands it to somebody else, along with the recurring compliance that follows.

What visibility actually looks like for this work

A single line reading "we also handle HMRC enquiries" on a services page will not rank and will not convert. What does:

A dedicated page for landlord disclosures. Not a paragraph inside a general tax page. One page, targeting the language landlords actually use, covering what the letter means, what the disclosure facility is, what it costs and what happens if they ignore it. This is the core of any serious search engine optimisation programme for a practice: one page per intent, written for the person searching rather than for HMRC.

Answers to the exact questions in the letter. Structured question-and-answer content is what gets pulled into search features and AI-generated answers. If your page answers "what is a certificate of tax position" better than anyone else's, you get surfaced when someone asks.

A site that converts panic into a booked call. High-intent visitors abandon slow pages and confusing contact forms. Getting the layout, the proof and the enquiry path right is web design work, and testing what actually moves the enquiry rate is conversion rate optimisation. A landlord disclosure page pulling 200 visits a month at a 2% enquiry rate is four leads. At 6% it is twelve, from identical traffic.

Proof. Anonymised outcomes, the credentials of whoever runs the disclosure work, and a clear statement of what the first conversation involves.

Where this fits the rest of your 2026 pipeline

This is not a standalone tactic. It sits inside a wider position that UK firms are able to take this year, because the compliance calendar keeps generating reasons for clients to move.

Landlords with qualifying property income are already inside the Making Tax Digital for income tax regime, which means a disclosure conversation and an MTD conversation are the same conversation. HMRC's own tax gap reporting points at exactly this population. And the volume of clients reviewing their adviser has produced the widest client switching window UK practices have seen in years.

If you want the full framework rather than a single campaign, our guide to digital marketing for accounting firms sets out how the pieces fit together, and our UK digital marketing services page covers how we run this for practices in Britain.

Talk it through

If you already do landlord disclosure work and nobody outside your existing client base knows it, that is a visibility problem with a known fix and a known return.

Message Aria on WhatsApp at triomaticmarketing.com for a straight answer on where your practice currently ranks for this work, or book a free 15-minute discovery call at calendly.com/hello-triomaticmarketing/15min and we will map the pages worth building first.

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