The Let Property Campaign is HMRC's route for landlords to disclose unpaid tax on UK or overseas rental income, on terms set out in advance rather than waiting for HMRC to find the gap itself. You notify HMRC that you intend to disclose, then have 90 days to work out and pay what you owe. It covers individual landlords letting residential property; it does not cover companies, trusts, or non-residential lettings such as a shop or garage.
What is the Let Property Campaign?
It is a standing HMRC disclosure facility, not a time-limited amnesty, aimed at landlords who have not declared some or all of their rental income. HMRC describes it as an opportunity to "get up to date" with tax on letting income, covering a single property, multiple properties, a room let above the Rent a Room Scheme threshold, holiday lettings, and property let while you live abroad. It also covers landlords who inherited a property and began letting it without realising the income needed to be declared.
Many landlords come to this because they received an HMRC nudge letter pointing to a mismatch between reported rental income and information HMRC already holds, for example from a letting agent or the Land Registry. You do not need a nudge letter to use the campaign; you can come forward on your own.
Who can use the campaign, and who cannot?
The campaign is for individual landlords with undisclosed UK or overseas rental income. According to HMRC's guidance, it does not extend to everyone with a property. Two exclusions matter most:
If HMRC has already told you it intends to open an enquiry or compliance check before you notify your own disclosure, your disclosure is unlikely to be accepted under the campaign's terms. In that situation, tell the officer handling the enquiry instead; a full and early disclosure can still influence any penalty.
How does the notify-then-disclose process work?
The process has two distinct steps, and mixing them up is one of the most common errors.
HMRC's guidance is direct on this point: if you are not sure how to calculate what you owe, or which years to include, you should get independent professional advice before you submit, because an incomplete or inaccurate disclosure can be rejected or investigated further.
How far back does HMRC go?
This depends on your behaviour, not a single fixed number of years, and HMRC asks you to self-assess which category applies to you as part of the disclosure. Broadly:
HMRC's guidance notes it expects most people who come forward to fall into the smaller categories, with the 20-year maximum reserved for those who deliberately understated income or told HMRC nothing at all. Getting your own behaviour category right matters: an incorrect self-assessment is itself a ground for HMRC to reject the disclosure, so if you are unsure which applies to you, take advice before you submit rather than guessing.
Penalties follow a similar behaviour-based structure. HMRC's guidance states penalties can reach up to 100% of the tax owed for UK income, and up to 200% where the liability involves an offshore element, though the rate you actually pay depends on your behaviour category and how fully and promptly you disclose. If you took reasonable care and still underpaid, HMRC's guidance says you will not pay a penalty at all in most such cases.
What about the gross rent versus profit confusion?
A frequent misunderstanding is treating the gross rent received as the taxable amount, rather than the profit after allowable expenses. You are taxed on rental profit, meaning rent received less allowable running costs of the letting, not the rent itself.
A related and separate point trips up landlords with mortgages: since the Section 24 rules took full effect, mortgage interest and other finance costs are no longer deducted from rental income before arriving at taxable profit. Instead, you get a basic-rate tax credit, currently a 20% credit for the 2026/27 tax year, applied after the tax on your full rental profit has been calculated. This can mean a landlord's taxable profit, and their tax bill, is higher than a simple "rent minus mortgage interest" calculation would suggest, which is one reason some landlords under-declare without intending to. HMRC's guidance on the finance cost restriction sets out worked examples. The 20% credit stays in place for 2026/27; it is due to rise to 22% only from 6 April 2027, alongside new property income tax rates, so do not apply the higher rate early.
What happens if I do nothing?
HMRC continues to receive third-party data, including from letting agents, the Land Registry and other sources, and can use it to identify landlords who have not declared letting income. If HMRC opens a compliance check or enquiry before you come forward, you lose the more favourable terms and lower penalty range available to someone who discloses voluntarily, and in the more serious cases HMRC can consider a criminal investigation rather than a civil one. Coming forward under the campaign, promptly and completely, is what keeps the lower end of the penalty range available.
Worked example: a decision walk-through
Example. Consider a landlord who let a second property for six years without declaring the rental income, believing wrongly that it fell below a tax-free threshold. She first checks whether she is eligible: she is an individual, the property is residential, and no enquiry has been opened against her, so the Let Property Campaign fits.
She then works through her own behaviour honestly. She registered for Self Assessment on time for her main income but never told HMRC about the letting income at all, which places her in the more serious "failed to notify" category rather than simple carelessness, since she did not report the income within the deadlines for the relevant years. Recognising that this affects both the number of years she needs to disclose and the penalty range, she takes advice before deciding how to categorise her behaviour and calculate what is owed, rather than assuming the lowest category applies.
Once she is confident in her figures, she notifies HMRC of her intention to disclose, receives her reference numbers, and uses the 90-day window to gather six years of bank statements and tenancy agreements, working with her adviser to calculate the profit, tax, interest and penalty for each year before submitting the disclosure and payment together.
What this means in practice
You can start today by pulling together tenancy agreements, bank statements and any records of expenses for every property you let, and using HMRC's Let Property questionnaire to check whether the campaign applies to you.
Working out your behaviour category, calculating profit correctly (including the Section 24 finance cost credit), and deciding how many years to include are best done with an adviser, because getting them wrong can see a disclosure rejected or investigated further.
If you are not sure whether your situation is a straightforward oversight or something HMRC could view as deliberate, that distinction is worth checking before you notify, not after.
Talk to us before you notify HMRC
If you have undeclared rental income and are not sure whether the Let Property Campaign is the right route, speak to speak to us before you contact HMRC. The first conversation covers which years and properties are affected, which behaviour category genuinely applies to you, and what the disclosure will involve. Call 020 8554 2135 or email info@visionconsulting.co.uk, or get in touch via our contact page.
By the Vision Consulting team.
This is general information, not advice. Your position depends on your circumstances.