HMRC Nudge Letter Response Playbook for Landlords with Property Income

HMRC nudge letters on property income are arriving in landlord mailboxes at a materially higher rate in 2026 than at any point in the regime's history. The driver is data: DAC7 platform reporting from Airbnb, Booking.com and similar platforms began on 1 January 2024 and is now feeding HMRC's risk-scoring algorithms; Land Registry cross-matches have become more granular; tenancy deposit scheme records are routinely sampled. The result is a wave of pre-enquiry letters inviting recipients to review and (if appropriate) disclose any undeclared property income.

This page is the response playbook. It explains what a nudge letter is, what it is not, the data sources that generate them, the four response options available to a landlord recipient, and the trade-offs between them. It is written for landlords reading the letter and deciding what to do next.

What a nudge letter is, and what it is not

A nudge letter is a pre-enquiry behavioural prompt. HMRC has information suggesting the recipient may have undeclared property income; the letter invites a review and (if appropriate) a disclosure or correction. The letter is not a formal enquiry under TMA 1970 section 9A, which requires a separate written notice of enquiry and which carries the full information-gathering power of a section 9A investigation.

Three structural points about nudge letters matter. First, they are not based on confirmed under-declaration; they are based on a data match. Recipients who correctly declare all rental income are not in breach of anything by receiving a letter. The legal basis for HMRC's data-gathering powers underlying nudge letters sits in HMRC's Property Income Manual at PIM2010 onwards for the rental-income tax framework and in HMRC's general information powers under Schedule 36 FA 2008 for the gathering side. Second, they have no statutory force. They do not start a section 9A enquiry, they do not extend any time limit, and they are not formally appealable. Third, ignoring them is recorded. HMRC's risk-scoring takes nudge-letter response patterns into account; non-response is a substantial escalator.

Why the volume has risen in 2024-2026

Four data sources have come together over recent tax years to drive the current nudge-letter volume:

• DAC7 platform reporting. Online accommodation, transport and personal-service platforms must report annual host income and identifying data to HMRC under the UK's implementation of the EU DAC7 directive (effective 1 January 2024). Hosts on Airbnb, Booking.com, Vrbo, SpareRoom and similar platforms are now visible to HMRC at a transactional level. UK-resident host income that does not match self-assessment returns is the single largest current trigger.
• Land Registry cross-matching. HMRC routinely cross-matches Land Registry property-ownership data against self-assessment returns. Multi-property owners with no rental income declared (or with mismatched rental figures across years) are flagged.
• Tenancy deposit scheme records. The mandatory deposit-protection schemes (DPS, MyDeposits, TDS) provide HMRC with tenant-deposit data that confirms a property is being rented even where the rental income is not declared.
• Mortgage data + Connect. Buy-to-let mortgage data, council-tax records, insurance records and other administrative data sources feed HMRC's Connect risk-scoring system, which surfaces multi-source matches as nudge-letter targets.

The cumulative effect is that the bar for HMRC to identify a landlord with possibly undeclared income has fallen materially. Landlords who relied on the practical difficulty of HMRC discovering rental income now face a data-driven enforcement environment.

The four response options

Option 1: Do nothing

Available but rarely the right choice. Doing nothing leaves the landlord exposed to HMRC's next step: either a formal section 9A enquiry (where the enquiry window is still open) or a discovery assessment under section 29 (where it is not). If undeclared income exists, doing nothing also forfeits access to the unprompted-disclosure floor under Schedule 24 paragraph 10 or the equivalent Schedule 41 floor. The penalty differential between unprompted (0 per cent careless / 20 per cent deliberate-not-concealed) and prompted (15 per cent careless / 35 per cent deliberate-not-concealed) is materially valuable on any non-trivial tax loss.

Doing nothing is only defensible where the landlord is genuinely confident that no undeclared income exists, that all returns are correctly filed, and that no concerns of any kind sit on the file. Even then, a short proactive response is usually a better posture.

Option 2: Voluntary disclosure via Let Property Campaign

The recommended route where undeclared residential rental income exists. The Let Property Campaign is HMRC's standing disclosure facility for landlords with undisclosed rental income. The process is three-step: notify HMRC of intent to disclose, calculate full tax + interest + penalty within 90 days of acknowledgment, pay on disclosure.

Critical operational point: a nudge letter is functionally a prompt, but HMRC operational practice has historically allowed unprompted-disclosure floors to apply where the landlord moves to LPC disclosure within the nudge-letter response window. The current practice should be verified with HMRC at the point of disclosure (the letter itself sometimes confirms the unprompted-floor availability). Where unprompted-floor access is confirmed, the LPC route delivers the most favourable penalty outcome consistent with full disclosure.

The LPC is residential-rental specific. Commercial property, mixed-use property, foreign rental property and other non-rental matters require different routes (the general Digital Disclosure Service for UK non-rental matters, the Worldwide Disclosure Facility for offshore).

Option 3: Await enquiry

Largely a sub-optimal option. Where undeclared income exists, awaiting formal enquiry forfeits the chance to disclose voluntarily and exposes the landlord to prompted-disclosure penalty floors. Where there is no undeclared income, awaiting enquiry is procedurally indifferent (HMRC may or may not open one) but commits the landlord to an enquiry-response posture rather than a proactive position.

The exception is where the landlord genuinely does not yet know whether undeclared income exists (for example, complex multi-property records that need a full review). In that case, the right interim response is to acknowledge the letter and request a short extension while the review is conducted, rather than to ignore the letter and await formal enquiry.

Option 4: Engage proactively where rental is correctly declared

Where the landlord's self-assessment returns correctly declare all rental income and the nudge letter is a data-driven match without underlying under-declaration, the right response is a short letter to HMRC confirming the review undertaken and the conclusion. The letter typically covers: the years in question; the rental income declared on each year's return; the box numbers on the SA105 supplementary page (or the SA106 for foreign rental); cross-references to the underlying records.

HMRC typically closes the file on receipt of a clean proactive response. The letter should be sent within the response window stated in the nudge letter, with copies retained for the landlord's records.

The penalty trade-off between options

The single largest practical consequence of getting the response wrong is the penalty differential between unprompted and prompted disclosure under Schedule 24 FA 2007 (for inaccuracy in already-filed returns) or Schedule 41 FA 2008 (for failure to notify chargeability at all).

The Schedule 24 differentials are 15 percentage points on careless (0 per cent unprompted vs 15 per cent prompted), 15 percentage points on deliberate-not-concealed (20 per cent vs 35 per cent), and 20 percentage points on deliberate-and-concealed (30 per cent vs 50 per cent). On a £40,000 tax loss careless case, the differential is £6,000. On a £100,000 deliberate-not-concealed case, it is £15,000.

The Schedule 41 differentials operate similarly with a 12-month qualifier on the non-deliberate-unprompted floor: disclosure within 12 months of when liability arose secures 0 per cent floor; outside the 12-month window the floor rises to 10 per cent.

Where access to the unprompted floor is in play, the response window discipline is decisive. Moving to LPC voluntary disclosure within the nudge-letter response window typically secures the unprompted floor (subject to HMRC's current operational practice); waiting until after the window closes typically forfeits it.

Reading the nudge letter carefully

Nudge letters from HMRC are not all the same. The body of the letter typically signals the data source HMRC is relying on and the specific concern HMRC has identified. Common variations:

• Generic "you may have rental income" letter. HMRC has a multi-source data match (Land Registry plus mortgage data, for example) but no specific transactional evidence. The letter invites general review and disclosure.
• Platform-specific letter (Airbnb / Booking.com / Vrbo). HMRC has DAC7 data showing platform income to a UK-resident host. The letter typically specifies the platform and may give the host the platform's reference.
• Specific-year letter. HMRC has identified a particular year as out of pattern (for example, a property purchase year with no following rental declaration). The letter focuses on that year.
• Multi-property letter. HMRC has cross-matched multiple Land Registry holdings against the recipient's self-assessment and is asking about all of them.

The specificity of the letter is the first clue to the strength of HMRC's underlying position. A generic letter often reflects a thin data match; a platform-specific or year-specific letter typically reflects a confirmed mismatch and is materially harder to defuse without disclosure or specific evidence.

What the response letter should contain

Where the response is a proactive confirmation that rental income is correctly declared, the response letter should be short but substantive. Useful contents:

• HMRC reference number and date of the nudge letter.
• The years HMRC is asking about.
• For each year, the rental income figure declared on the SA105 (or SA106 for foreign rental) and the box number on the form.
• The properties to which the declared income relates.
• Any specific data-source HMRC has flagged (for example, the platform name where DAC7 is the trigger) with confirmation that the declared figure includes that source.
• A short statement that the landlord has reviewed records and is satisfied that all rental income has been correctly returned.
• An offer to provide further information on request.

The response letter is not the place to raise unrelated tax positions, ask HMRC procedural questions, or volunteer information that has not been asked for. Stick to the rental-income position. The objective is to close the nudge-letter file, not to open a wider conversation.

What to do if records are incomplete

A material proportion of landlord nudge-letter responses are complicated by incomplete records: missing bank statements, lost lettings-agent reports, partial expense records. Where the underlying records are incomplete, the response should focus on:

• What records are available and the income figures they support.
• Why specific records are missing (storage, loss, change of accountant) and what reasonable steps were taken to maintain them.
• Where reconstruction is possible (for example, by requesting historic statements from banks or platforms).
• An offer of a reconstruction timeline if HMRC requests it.

Incomplete records do not preclude a defensible response, but they do shift the negotiating position. TMA 1970 section 12B requires record retention for five years from 31 January following the tax year for income tax purposes. Where records have not been kept to that standard, the section 12B penalty (up to £3,000 per year of failure) may be in play independently of any rental-income disclosure question.

How nudge-letter response sits alongside the broader enquiry framework

The nudge letter is the first communication in a potential enforcement sequence. The framework looks like this:

• Pre-enquiry behavioural prompt: the nudge letter. This page.
• Voluntary disclosure routes: LPC for rental, WDF for offshore, DDS for UK non-rental, CoP9 / CDF for deliberate-fraud with criminal exposure. See our CoP9 / CDF page for the criminal-immunity route.
• Formal enquiry: section 9A notice, information exchange, closure notice. See our closure notice mechanics page.
• Post-enquiry discovery: section 29 assessment, time-limit brackets. See our discovery assessment time limits page.
• Appeal: 30-day Notice of Appeal, HMRC review, FTT.

The nudge letter is the pre-enquiry trigger that determines whether the landlord ends up in the disclosure-routes column or in the formal-enquiry-and-appeals column. The right response to a nudge letter is the one that keeps the landlord in the disclosure-routes column where appropriate, or that demonstrates a clean position where no disclosure is needed.

Worked scenario: short-let host receives an Airbnb-flagged nudge letter

Background. A higher-rate landlord owns a flat in central Manchester used as a short-let on Airbnb. The flat generated approximately £24,000 of gross income across the 2024/25 tax year. The landlord, on the basis that "Airbnb income is below the rent-a-room threshold" (an incorrect understanding, since rent-a-room applies only to the landlord's main residence and not to a separate let property), did not declare the income on self-assessment.

Trigger. In April 2026, HMRC sends a nudge letter referencing DAC7 platform data showing 2024 platform income. Response window: 60 days.

Day 1-7. The landlord engages an accountant. The accountant confirms that rent-a-room does not apply because the flat is not the landlord's main residence; the entire £24,000 is taxable rental income subject to ordinary income-tax treatment. Allowable expenses are quantified at approximately £8,500 (mortgage interest restricted to a 20 per cent tax credit under section 24, agent fees, cleaning, utilities, repairs, insurance, council tax for void periods).

Day 8-21. The accountant prepares the LPC notification. Net rental profit for 2024/25 is approximately £15,500; additional income tax at 40 per cent is approximately £6,200; the section 24 mortgage-interest credit reclaim reduces the net liability slightly. Total tax loss across the disclosure window (2024/25 only, since the flat was first listed in 2024): approximately £5,800. The accountant also identifies that 2025/26 platform income (10 months) will need to be returned correctly on the upcoming self-assessment.

Day 22-30. LPC notification submitted. HMRC acknowledges and confirms unprompted-disclosure floor access (the disclosure was made within the nudge-letter response window). The Schedule 41 FA 2008 failure-to-notify regime applies (the landlord had never registered for self-assessment in respect of the let; the rental income source was new in 2024/25). Behaviour band: non-deliberate (genuine misunderstanding of rent-a-room). Disclosure is within 12 months of when liability arose (rental income started August 2024; the section 7 notification deadline was 5 October 2025; disclosure in May 2026 is approximately 8 months after the section 7 deadline, within the Sch 41 12-month qualifier for the 0 per cent unprompted floor).

Outcome. Total settlement: £5,800 tax + £0 penalty (0 per cent floor on unprompted within 12 months) + approximately £180 interest = £5,980. Plus accountant fee of £1,800. Total cost to landlord: £7,780. The 2025/26 position is brought into self-assessment correctly. Future Airbnb income will be returned annually on the SA105.

The scenario illustrates how the right response to a nudge letter (proactive LPC disclosure within the response window) can deliver an outcome at the lower end of the cost range. If the landlord had ignored the nudge letter and waited for HMRC to open a formal enquiry, the same tax loss would attract a prompted-disclosure penalty (10 per cent Sch 41 floor for non-deliberate prompted), namely £580 of penalty, on top of the tax and interest. The differential is small in this case because the underlying tax loss is small; on larger cases, the differential becomes material.

What to do in the first 14 days

The operational discipline on receipt of a nudge letter:

1. Day 1-3: Read the letter carefully. Identify the years HMRC is referring to, the data source HMRC is citing (if specified), and the response date.
2. Day 4-7: Conduct a quick review of the underlying records. Is rental income declared for the years in question? Are the declared figures consistent with platform data, deposit records, or other underlying evidence?
3. Day 8-14: If the review reveals undeclared income, engage an accountant or tax adviser and notify intent to disclose via LPC (or WDF for offshore). If the review confirms correct declaration, draft and send a proactive response letter. If the review reveals partial issues (some years correct, some not), draft a hybrid response acknowledging the issues and notifying disclosure on the problematic years.
4. Within the response window: Send the substantive response. For disclosure cases, the LPC notification + 90-day disclosure timeline starts running.

The single most expensive avoidable error is missing the response window because the issue was too complex to resolve quickly. Acknowledging the letter, requesting a short extension, and engaging professional advice is always preferable to silence.

If you have received an HMRC nudge letter on property income and need to work through the response options, the form at the foot of the page is the route to a structured first-pass assessment.