Range from the cheapest cat flap installation £48 (Queen of Flatpacks based in EN10) to the dearest cat flap installation £180 (LT Electrics based in CM16).
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 EN9 by posting a job with HaMuch and we will send it to carpenter & joiners in EN9.