under one policy ??

Tesco pet insurance!

pet plan are good

I got my 2 cats insured through the RSPCA They wouldnt put them under the 1 policy but give you a discount for every pet you insure after the first one. I pay 3.83 per month per cat and that is the gold cover which i think is really good.

Try Pet Plan

Direct line will as long as you own all three. We have three dogs in our house, but they have different owners so can't be on the same policy. Out of several different companies I have been with, Direct Line have by far been the best. The premiums are not expensive, but the service is good, and I got a years free membership with Petback Protect, and the option to turn that to lifetime mebership for £10 a month for a year. (Membership is usually around £100 a year, every year, and it is a really good service)