If you are a landlord with undeclared rental income, you are standing at a digital crossroads. On one path, you wait for HMRC to find you; on the other, you step forward first. In the world of UK tax, the label HMRC attaches to your disclosure—“Prompted” or “Unprompted”—is the single biggest factor in determining whether your penalty is a slap on the wrist or a financial catastrophe.
At Felix Accountants, we help landlords navigate the Let Property Campaign (LPC). Our goal is always to secure “Unprompted” status for our clients, as this simple distinction can save you tens of thousands of pounds in unnecessary fines.
1. The Definitions: What’s the Difference?
The distinction between these two terms is simpler than it sounds, but the timing is everything.
What is an Unprompted Disclosure?
An unprompted disclosure occurs when you tell HMRC about a tax irregularity before they have any reason to believe you have a problem. You are the one who initiates the conversation. Even if you only come forward because you heard about HMRC’s “Connect” system in the news, as long as they haven’t contacted you yet, it is unprompted.
What is a Prompted Disclosure?
A disclosure is “prompted” if you only come forward after HMRC has contacted you. This includes receiving a “nudge letter,” a notification of a compliance check, or a formal tax enquiry. HMRC’s view is that you aren’t being “honest”; you are simply “getting caught.”
2. The Penalty Gap: A Financial Comparison
HMRC uses a sliding scale for penalties based on your behavior and the “quality” of your disclosure. The difference between moving first (Unprompted) and moving second (Prompted) is stark.
| Behaviour Category | Unprompted Penalty Range | Prompted Penalty Range |
| Reasonable Care | 0% | 0% – 30% |
| Careless | 0% – 30% | 15% – 30% |
| Deliberate | 20% – 70% | 35% – 70% |
| Deliberate & Concealed | 30% – 100% | 50% – 100% |
Note: For offshore property income, penalties can reach as high as 200%.
The Real-World Impact:
Imagine you owe £20,000 in back-tax from a “Careless” error.
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Unprompted: With a good accountant, we can often negotiate this down to 0%, meaning you pay just the tax and interest.
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Prompted: You are guaranteed a minimum penalty of 15% (£3,000), plus the tax and interest.
3. Why the “Quality of Disclosure” Matters
Even within those ranges, your final penalty depends on three factors HMRC calls “Helping, Telling, and Giving.”
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Telling: Did you fully explain the error?
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Helping: Did you calculate the tax accurately?
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Giving: Did you provide all the bank statements and records requested?
By being unprompted and providing a “high-quality” disclosure via Felix Accountants, you give HMRC very little room to charge anything above the minimum.
4. The “Connect” Threat: Why You Can’t Wait
In 2026, the window for unprompted disclosures is closing fast. HMRC’s Connect system is now fully integrated with:
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The Land Registry: They know when you buy or sell.
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Letting Agents: They receive annual lists of all landlords and the rent they collect.
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Digital Platforms: Airbnb and Booking.com share host data directly with HMRC.
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Bank Interest: HMRC sees the interest you earn on your savings, which often flags “extra” wealth.
Once the system flags you and a nudge letter is printed, you lose the ability to make an unprompted disclosure. You have effectively “lost” the 0% penalty option.
5. Benefits of the Unprompted Let Property Campaign
Beyond just the lower fines, moving voluntarily through the LPC offers:
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No “Naming and Shaming”: HMRC maintains a public list of “Deliberate Tax Defaulters.” By coming forward voluntarily, you almost always avoid being added to this list.
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Immunity from Prosecution: While not a legal “guarantee,” HMRC rarely pursues criminal charges against those who make a full, honest, unprompted disclosure.
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Control of the Narrative: You get to explain the situation first, rather than defending yourself against HMRC’s assumptions.
6. How Felix Accountants Secures the Best Outcome
When you choose to disclose voluntarily, we don’t just send a cheque. We build a comprehensive Case for Leniency:
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Technical Analysis: We determine if your error was “Careless” or “Reasonable,” rather than “Deliberate.”
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Statutory Interest Calculation: We ensure you aren’t overpaying on interest.
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Representation: We act as your formal agent, meaning HMRC speaks to us, not you.
Frequently Asked Questions (FAQs)
Q1: I received a “Nudge Letter” yesterday. Is it too late for an unprompted disclosure?
Technically, yes. Once the letter arrives, the disclosure is “prompted.” However, by responding immediately and using the Let Property Campaign correctly, we can still argue for the absolute minimum of the prompted penalty range.
Q2: Can I be unprompted if I only disclose some of my properties?
No. A disclosure must be “Full and Complete.” If you disclose one property but hide another, and HMRC finds the second one later, they will view the entire disclosure as “Deliberate and Concealed,” which carries the highest penalties.
Q3: What if I didn’t know I had to pay tax?
This is often classed as “Careless” or “Failure to Notify.” If it’s unprompted, we can often get the penalty down to 0% or 10% by showing that it was a genuine misunderstanding of the rules.
Q4: Does unprompted disclosure take longer?
No. The process is identical: you notify HMRC, and then you have 90 days to submit the figures. The only difference is the “Unprompted” flag on your file, which makes the final bill much smaller.
Q5: Will HMRC audit my other business interests if I disclose my rental income?
Generally, no. The Let Property Campaign is a “ring-fenced” disclosure facility. While HMRC reserves the right to look elsewhere, if your LPC disclosure is professional and accurate, they usually accept it and close the file.
Don’t Wait for the Nudge
The difference between an Unprompted and Prompted disclosure is often the difference between a manageable settlement and financial ruin. If you know your tax affairs aren’t up to date, now is the time to act.
Contact Felix Accountants today. Let’s get your unprompted disclosure started before HMRC finds you.








