Written by: Faryal Raza Bhatti, Marketing Manager, Norton Insurance Brokers
Key takeaways
- Not declaring a pre-existing medical condition can invalidate your entire policy, not only a claim connected to that condition. A broken leg abroad can go unpaid because of an undeclared heart condition you never expected to claim on.
- Under the Consumer Insurance (Disclosure and Representations) Act 2012, you must take reasonable care not to misrepresent your health. If the insurer would not have offered cover had it known, it can void the policy and refuse all claims.
- The risk is widespread. In Norton’s 2026 survey, 35% of respondents had a medical condition that could affect their cover, and 26% admitted they find it hard to understand what their policies actually cover.
| In a nutshell, If you do not declare a pre-existing medical condition and then need to claim, the insurer can reduce the payout or refuse the claim altogether, and it can cancel the policy as though it never existed. This applies even when the claim has nothing to do with the undeclared condition, and even when the omission was an honest mistake. Declaring conditions accurately is what makes a policy valid. It rarely means being refused cover: specialist insurers price medical conditions routinely, and most travellers who declare are still able to arrange comprehensive cover. |
According to the Norton Survey of the Year 2026, which surveyed 549 UK homeowners and insurance customers, 35% had a medical condition that could affect their travel cover, yet 26% said they find it hard to understand what their policies include. That combination is exactly how undeclared conditions happen: not through dishonesty, but through a genuine misunderstanding of what has to be disclosed and what the consequences of silence are. This article sets out both, plainly.
What counts as a pre-existing medical condition?
A pre-existing condition is any diagnosed illness or injury you have had before buying the policy. Insurers expect the obvious ones declared, heart conditions, diabetes, cancer, respiratory conditions like COPD or asthma, and they also expect the ones people forget: high blood pressure, high cholesterol, a condition you take daily medication for but no longer think about, and anything you are currently under investigation for even without a diagnosis yet.
Mental health conditions such as anxiety and depression count too, and are declarable on the same basis as physical ones. The test is not how serious or how active the condition is. The test is whether it has been diagnosed, or whether you are waiting on a diagnosis. If a doctor has put a name to it, or is trying to, it belongs on the declaration.
What does the law actually say about non-disclosure?
Non-disclosure is governed by the Consumer Insurance (Disclosure and Representations) Act 2012, which places a duty on you to take reasonable care not to make a misrepresentation when you buy or renew cover. The old rule, which expected you to guess what the insurer wanted to know, is gone. Instead the insurer must ask clear questions, and you must answer them accurately.
The consequence depends on why the misrepresentation happened. If the insurer would still have offered cover but on different terms, it can apply those terms retrospectively to your claim. If it would have charged more, it can reduce the payout proportionately. And if it would not have offered cover at all had it known, it can void the policy entirely and refuse every claim. An honest, careless mistake is enough to trigger this. Deliberate concealment is treated more harshly still.
What happens to a claim if you have not declared something?
This is the part that catches people out. The penalty is not confined to the condition you left off. Void the policy and you void all of it.
Consider the most common example. A traveller does not declare stable, well-managed high blood pressure, reasoning that it never troubles them. On holiday they slip and break a leg. The medical bill abroad runs into tens of thousands of pounds. When the insurer processes the claim and reviews the medical history, it finds the undeclared condition, and it can challenge the whole claim on the grounds of non-disclosure, even though a broken leg has nothing to do with blood pressure. The cover the traveller was relying on evaporates at the worst possible moment.
The figures make the exposure concrete. Association of British Insurers data puts the average overseas medical claim at around £1,528, but the tail is severe: a medical evacuation from the USA to the UK averaged over £192,000 in 2024, and from Spain around £45,000. A voided policy turns any of those numbers into a personal debt.
