Does CIS apply to electricians?

Does CIS apply to electricians? Yes, for installing a whole electrical system, such as a full rewire. As of October 2026, HMRC treats repairs, extra sockets, burglar alarms, security CCTV and stand-alone data cabling as outside CIS, unless part of a wider building contract. Yes. HMRC's manual says replacing a whole system, such as a complete electrical rewire, counts as installing a system, which is within CIS. Not on its own. HMRC treats wiring extra sockets as extending a system, which is outside CIS, unless it is done under the same contract as building work such as an extension. Fire alarm and detection systems that only give an audible or visible warning are outside CIS. Fire detection that also sets off sprinklers or other structural fire protection is inside. Read the full answer, with every source, at rightotax.co.uk.