The Let Property Campaign (LPC) is HMRC's voluntary-disclosure route for residential landlords who have undeclared rental income on UK property. The campaign has been open continuously since 9 September 2013 and remains the primary disclosure entry point for individual landlords with historic exposure. What it offers, in concrete terms, is access to the Schedule 41 paragraph 13 unprompted-disclosure penalty floor: a numerical mitigation matrix that is materially more favourable than the alternative of HMRC discovering the position first.

This page is the benefits-quantification layer. We set out exactly what numbers LPC unlocks, what the closure-of-exposure benefit is in operational terms, what the cost of not disclosing looks like under HMRC's section 29 discovery powers and the section 36 extended-time-limit regime, and where LPC is the wrong route. We work through four representative landlord fact patterns to show the £-cost of LPC against the £-cost of waiting for HMRC.

The headline numerical benefit: Schedule 41 paragraph 13 mitigation floor

Schedule 41 to the Finance Act 2008 governs penalties for failure to notify chargeability to tax. A landlord with undeclared rental income who failed to notify under TMA 1970 section 7 within 6 months of the end of the tax year of liability is, in principle, exposed to a Schedule 41 penalty. The maximum penalty under paragraph 6 of Schedule 41 scales with the behaviour category:

  • Non-deliberate: up to 30% of the lost tax (UK matters), with offshore Category 1, 2, and 3 uplifts.
  • Deliberate but not concealed: up to 70% of the lost tax.
  • Deliberate and concealed: up to 100% of the lost tax.

Schedule 41 paragraph 13 reduces those maxima to a mitigation floor based on the quality of the disclosure, with the floor sitting materially lower for unprompted disclosure than for prompted disclosure. The mitigation floors are:

Unprompted disclosure (LPC route)

  • Non-deliberate, within 12 months of when liability arose: 0%
  • Non-deliberate, more than 12 months late: 10%
  • Deliberate but not concealed: 20%
  • Deliberate and concealed: 30%

Prompted disclosure (HMRC discovery first)

  • Non-deliberate: 10%
  • Deliberate but not concealed: 35%
  • Deliberate and concealed: 50%

The differential is the whole reason LPC exists as a route. For a landlord with non-deliberate exposure (the typical fact pattern: an accidental landlord who did not realise rental income required a self-assessment return, or a busy worker who let it slide for a few years), the LPC route caps the penalty at 10% of the lost tax. Waiting for HMRC discovery pushes the same fact pattern to 35%. On a tax exposure of £8,000, the differential is £800 vs £2,800: a saving of £2,000 in penalty alone before considering the operational benefits of voluntary disclosure.

The certainty-of-closure benefit

Once HMRC accepts a complete LPC disclosure and the liability is paid, the disclosed matter is closed for discovery purposes under TMA 1970 section 29. HMRC cannot subsequently re-open the disclosed years to look for additional tax, subject to two narrow exceptions in section 29(4) and (5): an incomplete disclosure and a disclosure that is deliberately inaccurate can be re-opened.

The closure benefit is operationally meaningful. A landlord who has lived with the background anxiety of historic undeclared rental income gains a finality on the disclosed years. Future HMRC nudge letters on the same period can be answered with the LPC reference; future risk-flag triggers on Land Registry / agent-commission / bank-data sources are deflected to the closed disclosure. The landlord can move forward to MTD ITSA from 6 April 2026 with a clean historic position.

The corollary is that the disclosure must be complete. A partial disclosure that omits material rental income or expenses leaves the position open under section 29(4). The discipline at disclosure stage is to scope the full historic period (all relevant tax years, all relevant rental properties, all relevant income streams) and to document the disclosure figures clearly enough that HMRC has no operational reason to look behind them.

The three-step LPC operational cycle

LPC sits inside HMRC's Digital Disclosure Service (DDS) at the gov.uk landlord-disclosure portal. The cycle has three steps:

Step 1: Notification

The notification is a short online form on the gov.uk LPC landing page. It asks the landlord to identify the type of property income, the approximate periods involved, and the contact details. HMRC issues a Disclosure Reference Number (DRN) in response. The notification itself carries no penalty consequence; it is the act that opens the disclosure window and converts the position from HMRC-discoverable to unprompted-disclosed.

The discipline is to notify before HMRC opens any formal contact on the matter. Once HMRC has issued a section 9A enquiry or a section 29 discovery assessment, the unprompted-disclosure window has closed. A nudge letter from HMRC is informal contact, not a formal enquiry, and a disclosure filed within the nudge-letter response window can still be treated as unprompted in HMRC's operational practice.

Step 2: Disclosure within 90 days

The full disclosure is due within 90 days of HMRC's acknowledgment of the notification. The disclosure comprises the tax computation for each year, the supporting records, and a behaviour explanation that determines the Schedule 41 paragraph 13 mitigation floor.

The behaviour explanation should identify the conduct against the Schedule 41 paragraph 5 behaviour categories: non-deliberate (an oversight, mistake, or misunderstanding), deliberate but not concealed (an intentional decision not to notify with no further concealment steps), or deliberate and concealed (intentional non-notification with additional concealment such as undisclosed bank accounts, false bookkeeping, or routing income through third parties). The behaviour category drives the floor and the disclosure should not over-classify the conduct: a non-deliberate fact pattern should be presented as non-deliberate.

Step 3: Payment

Payment is due in full at the close of the 90-day window. Where the lump sum is not feasible, HMRC will typically agree a time-to-pay arrangement under TMA 1970 section 108 and the Commissioners for Revenue and Customs Act 2005. Interest under TMA 1970 section 86 continues to accrue at the official rate during any time-to-pay period; the closure-of-exposure benefit is not blocked by time-to-pay.

Worked example 1: £40,000 undisclosed across 4 years, LPC vs counterfactual

Mr Larchwood owns a single BTL flat in Birmingham, let since 2021. Gross rents are £14,000 per year; mortgage interest, agent fees, and repairs leave around £10,000 net rental profit. He has never declared the income on his self-assessment return because he assumed (incorrectly) that his letting agent's payment processing or his employer's PAYE arrangement picked it up. Four tax years are undisclosed (2021/22, 2022/23, 2023/24, 2024/25); total net rental profit around £40,000. His marginal income tax rate is 20% (basic-rate).

LPC route under Schedule 41 unprompted floor

  • Tax: £40,000 × 20% = £8,000 income tax owed.
  • Interest under TMA 1970 section 86: cumulative around £1,000 over the 4-year arrears period at the prevailing HMRC interest rate.
  • Schedule 41 paragraph 13 unprompted floor: non-deliberate after 12 months = 10%. Penalty: 10% × £8,000 = £800.
  • LPC total settlement: £9,800.

Counterfactual: HMRC discovery via nudge letter

  • Tax: £8,000 (same).
  • Interest: £1,000 (same).
  • Schedule 41 paragraph 13 prompted floor: non-deliberate prompted = 35%. Penalty: 35% × £8,000 = £2,800.
  • Counterfactual total: £11,800.

The LPC benefit on these facts is £2,000 saved on penalty alone, plus the certainty-of-closure benefit on the four years, plus avoidance of the section 36 extended-time-limit reach if HMRC's discovery argument supported a careless-behaviour escalation to 6 years (which would have brought 2019/20 and 2020/21 into scope on prompted-floor terms).

Worked example 2: offshore rental income (LPC not eligible, WDF instead)

Mrs Chetwood owns 3 properties in Portugal let to tourists since 2014. She is UK-resident and UK-domiciled. She has never declared the Portuguese rental on her UK return, mistakenly believing that Portuguese withholding tax was a final UK tax credit. Gross Portuguese rents are €30,000 per year over 11 years.

The routing decision: LPC is UK-residential-rental-only. Mrs Chetwood's offshore rentals route via the Worldwide Disclosure Facility (WDF) inside the DDS umbrella, with the Schedule 18 FA 2017 Failure-to-Correct overlay biting hard on pre-30-September-2018 years.

Cost projection: for the pre-September-2018 years (2014 to 2018), the FtC minimum penalty is 200% of unpaid UK tax, reducible to 100% on a complete unprompted disclosure. For the post-September-2018 years, the standard Schedule 41 unprompted floor applies (10% non-deliberate after 12 months). The asset-based penalty (up to 10% of property value) kicks in where lost tax exceeds £25,000 in any tax year.

The reason this example sits in an LPC-benefits page is the boundary: a landlord with offshore property income is not eligible for LPC and faces a materially harder cost-benefit profile via WDF. The signpost is that the LPC mitigation matrix discussed above is UK-only; the offshore equivalent under WDF + FtC is much less favourable.

Worked example 3: cost of waiting through a nudge letter

Mrs Helmesley owns 2 BTL properties; 3 tax years are undisclosed with around £18,000 per year net rental profit. Total undisclosed profit is £54,000; basic-rate tax £10,800. She has been considering LPC for 6 months but has not yet acted. HMRC issues a nudge letter referencing rental income on Land Registry records and asking her to review and respond within 60 days.

The nudge letter does not automatically convert the disclosure to prompted for Schedule 41 purposes. HMRC's operational practice is that a nudge letter is informal contact and a disclosure made in response to it can still be treated as unprompted, provided the disclosure is filed within the nudge-letter response window AND before HMRC opens a formal section 9A enquiry or issues a section 29 discovery assessment.

The decision-point for Mrs Helmesley: notify LPC within the 60-day nudge-letter response window. The unprompted floor at 10% applies, the penalty is £1,080 on £10,800 tax, and the matter closes on agreed terms. If she delays past the response window and HMRC escalates to a formal section 9A enquiry, the disclosure becomes prompted (35% non-deliberate floor), the penalty becomes £3,780, and the section 36 6-year careless-behaviour reach may bring older years into scope.

The cost of waiting on these facts: around £2,700 in additional penalty alone. The cost-of-waiting curve scales with the underlying tax exposure: every £10,000 of additional tax saved-into-prompted-disclosure costs roughly £2,500 extra in penalty.

Worked example 4: joint property under Form 17 with one-spouse disclosure

Mr and Mrs Pickford own a joint BTL property at 75% Mr Pickford and 25% Mrs Pickford under a Form 17 election made in 2019. Mr Pickford's 75% share produces around £15,000 per year net rental profit; Mrs Pickford's 25% share produces around £5,000. Mr Pickford declared his share each year. Mrs Pickford did not, having assumed her share was de minimis below the £1,000 property allowance.

The £1,000 property allowance does not cover £5,000 net profit. Mrs Pickford has a notification obligation under TMA 1970 section 7 for each year that her net rental profit exceeded the allowance. The LPC route is open to her alone for her 25% share: 4 tax years × £5,000 net profit = £20,000 net rental profit, basic-rate tax £4,000, Schedule 41 unprompted 10% floor → £400 penalty plus interest. Mr Pickford's return is already complete and accurate; he does not need to use LPC.

Joint-property cases under Form 17 elections frequently produce uneven-disclosure scenarios: one spouse's return is complete and the other's is not. LPC is filed at the individual level, so the spouse with the disclosure obligation files LPC alone and the spouse with the clean return continues as normal. The disclosure does not pull the other spouse into HMRC's attention.

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The cost of not disclosing: the three counterfactual layers

The counterfactual to LPC is HMRC discovering the position first. Three statutory layers drive the cost differential:

Layer 1: Schedule 41 prompted-disclosure floor

Once HMRC has contacted the landlord on the matter (formal enquiry under TMA 1970 section 9A, discovery assessment under section 29, or formal information notice under Schedule 36 FA 2008), the unprompted floor closes and the prompted floor applies: 10% non-deliberate, 35% deliberate not concealed, 50% deliberate and concealed. On the same underlying tax, the penalty is typically 2 to 5 times higher.

Layer 2: section 36 extended-time-limit assessment

TMA 1970 section 34 sets the ordinary assessment window at 4 years from the end of the tax year. Section 36(1) extends to 6 years where the lost tax is attributable to careless behaviour. Section 36(1A) extends to 20 years where the lost tax is attributable to deliberate behaviour. Section 36A (inserted by FA 2019) extends to 12 years for offshore innocent error.

For a landlord with several years of undisclosed rental income, the section 36 extended reach can pull additional years into scope that would otherwise have fallen outside the ordinary 4-year window. The LPC disclosure can be scoped to the same period the landlord would offer voluntarily; HMRC discovery, by contrast, can reach further on careless-or-deliberate grounds.

Layer 3: section 86 interest accrual

Interest on unpaid income tax under TMA 1970 section 86 accrues continuously from the date the tax was originally due. The rate is set by reference to the Bank of England base rate and re-fixed periodically. For a landlord with 4 years of undeclared rental income at £2,000 of underpaid tax per year, the cumulative interest at the prevailing rate is typically £400 to £700 by the time of disclosure. Interest is not mitigated by the LPC route: the LPC benefit is on the penalty layer only.

The combined effect of the three layers explains why the LPC benefit is multi-dimensional. The penalty differential is the headline £-saving; the closure-of-exposure benefit is the operational certainty; the assessment-reach benefit limits the period at risk; and the interest layer accrues regardless and is removed from the calculus by paying earlier.

Where LPC is the wrong route

LPC is not the right route in three situations:

  1. Offshore property income. LPC is UK-residential-rental-only. Offshore matters route through WDF inside the DDS umbrella, with the FtC overlay for pre-September-2018 years.
  2. Limited company holdings. LPC is for individual landlords and certain trustees. Limited companies with undisclosed corporation tax exposure use the general DDS catch-all route or a corporate disclosure process via HMRC's large-business / mid-tier directorate.
  3. Deliberate-fraud cases with criminal exposure. LPC is a civil-resolution mechanism. It does not confer criminal-prosecution immunity. Deliberate-and-concealed exposure with potential cheat-the-public-revenue or false-accounting offences should route through the Contractual Disclosure Facility (CDF) under Code of Practice 9 instead.

The boundary at the deliberate-fraud end is the most operationally important. A landlord with multiple undisclosed bank accounts in family-member names, false bookkeeping, or systematic concealment over many years should not file LPC without first taking advice from a tax-investigation specialist solicitor. CoP9 / CDF protects against criminal prosecution for the disclosed conduct; LPC does not, and an LPC disclosure that crystallises deliberate-and-concealed conduct can give HMRC the evidential foundation for a parallel criminal investigation.

Reasonable excuse: a floor below the LPC floor

The Schedule 41 paragraph 13 mitigation floor is not the only defensive lever. Schedule 41 paragraph 20 disapplies the failure-to-notify penalty entirely where the landlord had a reasonable excuse for the failure and rectified the position within a reasonable time of the excuse ceasing. The Upper Tribunal in Perrin v HMRC [2018] UKUT 156 (TCC) set out the controlling four-stage test.

Excuses that typically succeed: serious illness of the landlord (medical evidence required), bereavement close to the notification deadline, documented system failure (HMRC gateway outage, payroll software outage, accountant's office fire), unexpected events outside the landlord's control. Excuses that typically fail: pressure of work, reliance on a third party that let the landlord down (unless reasonable care was taken), ignorance of the obligation, computer or software problems unless widespread.

Where reasonable excuse is available, the penalty falls to nil and the LPC mitigation floor becomes the fallback. The two defences run independently: a landlord with both should file LPC with the reasonable-excuse argument in the behaviour explanation. The worst case is the floor; the best case is nil.

The forward path after LPC

Once the LPC disclosure is accepted and paid, three forward-facing obligations matter:

  • Continuing rental income from the disclosed period onwards must be brought into the regular self-assessment cycle. The LPC closes the historic years; the future years run on standard self-assessment.
  • MTD ITSA from 6 April 2026. Where the landlord's qualifying property and trading income exceeds the MTD ITSA threshold (£50,000 in phase 1 from 6 April 2026; £30,000 in phase 2 from 6 April 2027; £20,000 in phase 3 from 6 April 2028), the future cycle moves into quarterly MTD ITSA submissions plus an annual final declaration.
  • Record-keeping under TMA 1970 section 12B continues regardless of filing mode. The 5-year-from-31-January floor is the statutory minimum; the firm's practical recommendation for property businesses is 7 years.

The closure benefit is on the historic disclosed period. The forward obligation is fresh each year. A landlord who has used LPC for a 4-year historic catch-up still has to file 2025/26 on time and to start the MTD ITSA cycle on 6 April 2026 if their qualifying income crosses the threshold.

How this page sits with the other LPC pages on this site

This page is the benefits-quantification layer of the LPC pillar. The other LPC pages on this site cover adjacent angles:

  • The general orientation page (know about the Let Property Campaign) covers what LPC is and how it fits into HMRC's voluntary-disclosure architecture.
  • The umbrella page on HMRC's Digital Disclosure Service shows where LPC sits among WDF, CTP, and the general DDS catch-all.
  • The penalty-calculator page lets the landlord sketch the likely penalty floor on their specific facts.
  • The why-voluntary-disclosure-makes-sense page covers the broader decision-theoretic case for moving early.
  • The missed-taxes-rescue page covers the scenario where the omission has run for many years and HMRC is already showing risk-flag signals.

Read this page if your question is "what specifically do I gain by using LPC, in £-terms". Read the calculator page if your question is "what penalty would I pay on my exact facts". Read the orientation page if your question is "what is LPC". Read the offshore page (WDF / DDS umbrella) if your property income has any foreign element.

If you have identified historic undeclared rental income on UK property and you would like a steer on whether LPC is the right route on your facts (and what the £-cost is going to look like), we work with landlords on the disclosure scope, the behaviour explanation, the documentation pack, and the negotiation with HMRC on the final settlement.