How does pet insurance excess and co-payment work in the UK?
A plain-English guide to the two amounts that decide how much of a vet bill you pay before the insurer does - the fixed excess you pay per condition each policy year, and the percentage co-payment that is increasingly compulsory as pets get older. We walk through the maths with a worked example so you can read any policy with confidence.
The essentials in 30 seconds
- Excess is a fixed amount you pay towards a claim - typically per condition, per policy year - before the insurer pays the rest.
- Co-payment is an added percentage of the remaining claim that you also pay, increasingly compulsory as your pet ages.
- On older pets you can face both at once: the fixed excess first, then a percentage of whatever is left.
- A higher excess or co-payment lowers your premium, but means you pay more out of pocket whenever you claim.
A £600 vet bill, step by step
Imagine a treatment that costs £600 on a policy with a £90 fixed excess and a 20% co-payment. The excess comes off first; the co-payment then applies to whatever is left.
| Step | Calculation | Amount |
|---|---|---|
| Vet bill | Total cost of treatment | £600.00 |
| Less fixed excess | You pay the first £90 | −£90.00 |
| Remaining claim | £600 − £90 | £510.00 |
| Co-payment (20% of remainder) | 20% × £510 | £102.00 |
| You pay in total | Excess £90 + co-payment £102 | £192.00 |
| Insurer pays | £510 − £102 | £408.00 |
Indicative example for orientation only - the order of excess and co-payment, the percentages and the limits are set by each insurer’s own policy wording. Not a quote.
The types of excess and co-payment you will meet
Most UK pet policies combine more than one of the charges below. Reading the policy schedule for each one is the only reliable way to know what a claim will actually cost you.
| Type | How it works | What it means for you |
|---|---|---|
| Fixed excess | A set £ amount (often £75–£150) deducted from the claim | Predictable; you always pay this first when you claim |
| Percentage excess / co-payment | A percentage (commonly 10–20%) of the claim, or of the amount left after a fixed excess | Scales with the bill - the bigger the claim, the more you pay |
| Compulsory excess / co-payment | Applied automatically, usually triggered once a pet reaches a set age | You cannot remove it; common on older and senior pets |
| Voluntary excess | An extra amount you choose to add to lower your premium | Cuts the premium, but raises what you pay at claim time |
| Per condition, per year | The excess applies separately to each condition, and resets each policy year | Several conditions, or a claim spanning a renewal, can mean paying the excess more than once |
Structures vary by insurer. Always check whether the co-payment is taken before or after the fixed excess, and at what age it begins. Not a quote.
Why co-payments climb as your pet gets older
Pet insurance is priced on how likely and how costly claims are - and both rise sharply with age. Older pets develop more chronic and age-related conditions, so insurers expect to pay out more often and for longer. Many policies respond by introducing a compulsory percentage co-payment once a pet passes a set age (often somewhere in the senior years), in addition to the usual fixed excess.
Market analysis of policy wordings - the kind compiled by ratings firms such as Defaqto - shows this pattern has become steadily more common: a growing share of policies apply an age-based co-payment, and the percentage charged tends to step up with each age band. It is a normal, market-wide feature rather than something unique to one insurer, and it is one of the main reasons a senior pet’s claims feel more expensive even when the headline premium looks similar. For how age also moves the premium itself, see our guide to pet insurance cost in the UK.
What to check before you buy
- Is the excess fixed, a percentage, or both? Both is common on older pets.
- Is it per condition, per year? If so, you may pay it again for a new condition or at renewal.
- When does the co-payment start? Check the exact age the compulsory percentage kicks in.
- What order are charges applied? Co-payment before or after the fixed excess changes the total - as our worked example shows.
- What is the vet-fee limit? A higher limit means more cover, but usually a higher premium.
- Is any voluntary excess worth it? Weigh the premium saving against what you would pay if you claimed.
Pet insurance excess & co-payment FAQs
Information only - not financial advice. Figures and examples are indicative, to aid understanding, and are not quotes; your actual excess, co-payment and premium depend on your pet, policy and insurer. My Insurance Expert is not an FCA-authorised intermediary and does not arrange or sell policies. Last updated: 2026-06-13