On an insurance policy, it's the amount you have to "meet" before the company will make a payment
[DOC] [TLE] Claims explained - Understand Insurance [PAR] The policy you buy is a promise of assistance when things go wrong, ... You will 
need to provide proof it is a genuine claim and the insurer will need to be certain 
... Insurance companies try to make the claims process as smooth as possible, 
but ... Before you claim ... can check on the amount of excess you may need to 
pay.