Range from the cheapest cat flap installation £100 (PHM based in SS14) to the dearest cat flap installation £236 (We are flooring based in CM3).
Comparing carpenter & joiners estimates for installing a cat flap gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to fit a cat flap in SS13 by posting a job with HaMuch and we will send it to carpenter & joiners in SS13.