Range from the cheapest fitting of a smoke alarm £54 (Dingers Electrics Ltd based in W7) to the dearest fitting of a smoke alarm £174 (ThePlumbers.org based in TW7).
Comparing electricians estimates for fitting smoke detectors 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 fire alarm in TW8 by posting a job with HaMuch and we will send it to electricians in TW8.