HMRC Let Property Campaign Explained: How to Disclose Undeclared Rental Income

What the Let Property Campaign is

The Let Property Campaign is a disclosure facility run by HMRC for residential landlords who have failed to declare some or all of their rental income. It was launched in 2013 and remains open in 2026 with no announced end date. It allows landlords to come forward voluntarily, calculate the tax due (with HMRC guidance), and pay with reduced penalties compared to what HMRC would impose if they discovered the underpayment themselves.

The campaign exists because HMRC estimates that hundreds of thousands of UK landlords have either accidentally or deliberately failed to declare rental income, and that the lost tax runs into hundreds of millions per year. Voluntary disclosure is cheaper for HMRC than investigation, so they offer a meaningful penalty discount for landlords who come forward.

Who can use it

The Let Property Campaign is open to:

• Individual landlords with rental income from UK or overseas property
• Trusts and partnerships
• Landlords who have never registered with HMRC for the property income
• Landlords who have registered but under-declared
• Both deliberate non-disclosure and innocent omission

It is not available to:

• Companies (limited companies use a different process)
• Landlords already under HMRC investigation for the same income

What you must declare

Everything that has not been declared. The disclosure must cover:

• All undeclared rental income (gross rent received)
• Allowable expenses (mortgage interest, repairs, agent fees, insurance, etc.)
• Net rental profit
• The years in which the income was earned
• Any capital gains tax on previous property sales that was not paid

How far back do you have to go

The look-back period depends on whether the underpayment was careless, deliberate, or innocent error:

• Careless error: 6 years
• Deliberate underpayment: 20 years
• Innocent error (taking reasonable care): 4 years

You decide which category applies to your situation, but HMRC will challenge if they think you are understating the look-back period. For most landlords who simply forgot or did not realise they had to declare, "careless" is the right category and the look-back is 6 years.

Penalties

The penalty is a percentage of the tax owed, on top of the tax itself plus interest. Under the Let Property Campaign, the discounted penalty rates are:

• Careless, prompted disclosure: 0% to 30%
• Careless, unprompted disclosure: 0% to 30% (lower end)
• Deliberate, prompted disclosure: 35% to 70%
• Deliberate, unprompted disclosure: 20% to 50%

If HMRC discovers the underpayment without you coming forward, the penalties can be 100% or higher, plus possible criminal prosecution for deliberate fraud.

The lower end of the range applies if you cooperate fully, are open about everything, and help HMRC understand the position quickly. The higher end applies if you make HMRC's job harder.

How to make a disclosure

1. Notify HMRC of intent to disclose through the Let Property Campaign online service. You receive a Disclosure Reference Number (DRN).

2. Calculate the tax owed for each year, including allowable expenses. HMRC's guide is detailed.

3. Calculate interest on the underpaid tax for each year (HMRC publishes the rates).

4. Calculate penalties using the prompted/unprompted ranges above.

5. Submit the disclosure with full payment within 90 days of receiving the DRN.

6. HMRC accepts or queries the disclosure. Most accepted disclosures close within 6 months.

If you cannot afford the full payment in 90 days, you can apply for a time-to-pay arrangement spreading the payment over up to 12 months (longer in some cases).

Why come forward

The financial argument is straightforward. HMRC has data sources they did not have a few years ago:

• Letting agent reports under the Letting Agent Tax Information Reporting requirement
• Rent deposit scheme data
• Council tax records
• Land Registry purchase records cross-referenced against income declarations
• Information sharing with foreign tax authorities for overseas property

The chance of HMRC discovering undeclared rental income is much higher in 2026 than it was 5 years ago. The penalty discount for coming forward is significant. For most landlords the question is when to disclose, not whether.

Getting professional help

For all but the simplest disclosures, an accountant who specialises in property tax is worth the fee. They can confirm your look-back period, calculate the tax accurately, structure the disclosure to put you in the best light, and negotiate the penalty range with HMRC.

Verifying property records

Property Passport UK shows the full sold price history and tenure data for every property in England and Wales, sourced directly from HM Land Registry. Search any address at [/search](/search) to confirm the dates and details of any property sale, which can help verify the figures you need for your disclosure.

Look up the property data behind your tax decisions

Property Passport UK shows verified data for every one of the 19.35 million properties in England and Wales: tenure, EPC, sold prices, flood risk, listed status. Use it to research before you buy a second home, plan a sale, or work out a tax position. Search any address at [/search](/search). Every fact comes from an official UK government source.

Related guides

• Stamp duty second home explained
• CGT on second home UK
• Private residence relief explained
• Inheritance tax on property