Most types of insurance require you to pay an excess, which is a fixed amount which you would pay towards the amount you intend to claim for. The excess is then deducted from the total amount you claim for, which is worth bearing in mind if your vet bills were £100 and your excess is £95 - you would only be claiming for £5.
There is no set or standard policy excess, and your provider might ask that you pay an excess per claim, or per condition. If you pay your excess per claim, you will need to pay your excess every time you make a claim. If you pay your excess per condition, you will pay it once a year, towards any claims in association with each condition your pet has.
On top of your fixed excess, your insurer might ask you to contribute a co-payment towards a claim. Read more about co-insurance here.
An excess can also increase as your pet gets older - this is because they are more likely to become poorly, and as a result you are more likely to claim.
If you have any concerns or queries regarding an excess in line with a specific policy, we would suggest getting in contact with them directly.