UK SIC 2007 · 43221

Plumbing, heat and air-conditioning installation

UK plumbers, heating engineers, and HVAC contractors, domestic and commercial. Includes boiler installations, central heating, AC fit-outs, and ventilation systems. Distinct from 43222 (other heat installation, niche industrial work).

~65,000 active UK ltds filed under this code on Companies House.

Related SIC codes

43210, Electrical installation
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43222, Other heat installation
43229, Other plumbing-related installation activities

Who uses this code in B2B outreach

Lead generation for UK construction firms and trades

Find UK contractors, developers, and trades by SIC and region.

Where SIC 43221 clusters in the UK

LondonManchesterBirminghamLeeds

About SIC 43221

Are gas-safe heating engineers a separate SIC?

No, gas-safe registration is a regulatory status, not a SIC distinction. UK heating engineers all file 43221 regardless of which fuel types they're certified for.

How seasonal are SIC 43221 prospects?

Heavily, winter (Sept-Feb) is the busy season. Outreach targeting plumbers tends to perform better in spring/summer when they have more inbox attention.

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