Range from the cheapest window sill replacement £380 (AOM Builders Ltd based in UB4) to the dearest window sill replacement £468 (Facelift Electrical Services Ltd based in UB4).
Comparing carpenter and joiners estimates for replacing a window sill 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 replace a window sill in UB8 by posting a job with HaMuch and we will send it to carpenter and joiners in UB8.

"We would like the window sills replaced in our bay window"
UB8