Intro
Most landlords don’t expect the letter.
And when it arrives, the first question is usually:
“How serious is this?”
Because at that point, it’s no longer about whether HMRC knows.
It’s about what they do next.
And this is where the situation changes.
If you’re already dealing with HMRC contact, you can book a call here: https://calendly.com/graceca-ltd/paid-tax-property-consultation
What triggers HMRC action
This is something I see quite often.
By the time HMRC contacts you, they are not guessing.
They already have information.
This can come from:
- Letting agents
- Land Registry records
- Mortgage data
- Tenancy deposit schemes
- Data matching across systems
So when the letter arrives, it usually means:
They believe there is something to check
Not that they’re starting from scratch.
This usually links back to rental income that hasn’t been fully reported over time — something I’ve covered in more detail in my guide on undeclared rental income in the UK.
Why this is where it shifts
At the beginning, most people think:
- It’s just one year
- It’s a small issue
- It can be quickly explained
But in reality:
This is often where things expand
Because once HMRC starts looking:
- They don’t stop at one year
- They look for patterns
- They check consistency
And that’s when it becomes more than expected.
What happens next
This is the part people underestimate.
You may be asked to:
- Provide records going back several years
- Explain gaps or inconsistencies
- Confirm how income has been treated
And depending on what HMRC finds:
- The scope can widen
- The timeline can extend
- The cost can increase
Not always – But often enough that it needs to be taken seriously
How much could this cost?
At this stage, people usually ask:
“How much is this going to cost me?”
And the honest answer is:
👉 It depends on the situation
But what I can say is this:
I’ve seen this go from a few thousand… to much more — depending on the position and how it’s handled.
And if you’re trying to understand what that might look like in your own situation, I’ve explained this further in my breakdown of How much tax you might owe on undeclared rental income.
Where people go wrong
The biggest mistake I see?
Waiting too long to deal with it properly
Hoping:
- It will go away
- It’s not serious
- It’s just a simple explanation
But by the time HMRC is involved:
👉 It’s already past that point
Watch the full breakdown
HMRC Found Your Rental Income — What Happens Next?
Video is live tomorrow
What you should do now
If you’re in this situation – or you think you might be —
Don’t guess your way through it.
Because the way this is handled early on, can make a significant difference to the outcome.
In many cases, this leads to a formal disclosure — often through the Let Property Campaign disclosure process, which allows you to bring things up to date properly.
👉 Book a 30-minute call here: https://calendly.com/graceca-ltd/paid-tax-property-consultation
On the call, we will look at:
- What HMRC is likely to do
- Where you currently stand
- What your next step should be