Construction SIC codes sit in three divisions: 41 for buildings and development, 42 for civil engineering and 43 for specialist trades. The right choice depends on who buys from you, because a main contractor, a groundworks firm and a sole trader roofer are very different customers.
Results Driven Marketing (RD Marketing) wrote this guide for suppliers who sell to the construction sector. We sell B2B data, so we have an interest in the subject. To keep it useful, we link our sources and show who a SIC search leaves out. For the basics, read what an SIC code is.
Written by Iain Irvin, Director of RD Marketing. Iain worked in telesales, business development and sales management before starting the business, and has more than 15 years of experience in B2B marketing data and lead generation. Codes, counts and sources checked on 5 November 2026.
Contents
- Which Construction SIC Codes Fit Your Customer?
- Key Construction SIC Codes
- Every Construction SIC Code
- Who Construction SIC Codes Leave Out
- Construction SIC Codes Under SIC 2026
- How to Build a Construction List
- How We Checked This
- Frequently Asked Questions
- RD Marketing Services That Can Help
- Talk to Us
Which Construction SIC Codes Fit Your Customer?
Start with the type of firm you sell to, then choose the codes. Take care with 41100, development of building projects. It has 116,907 active companies, more than any other code in Divisions 41 to 43, and a developer may not build anything itself.
| If you sell to | Start with | Worth knowing |
|---|---|---|
| Main contractors and housebuilders | 41201, 41202 | Buying is often project-based |
| Property developers | 41100 | May commission work and not build it |
| Infrastructure contractors | Division 42 | Often larger firms and public contracts |
| Trades and subcontractors | Division 43 | Many small firms, so include sole trader data |
| Architects and engineers | 71111, 71129 | Outside construction, in Section M |
| Builders merchants | 46730, 47520 | Wholesale and retail, in Section G |
Key Construction SIC Codes
These codes cover common supplier targets. Do not add the counts together, because a company can list up to four codes.
| SIC code | Companies House description | Active companies | SIC 2026 code | What to know |
|---|---|---|---|---|
| 41201 | Construction of commercial buildings | 44,810 | 41.01, 43.99, 91.30 | Main contractors: commercial |
| 41202 | Construction of domestic buildings | 103,580 | 41.02, 43.99, 91.30 | Housebuilders and builders |
| 41100 | Development of building projects | 116,907 | 68.12 | Developers, not always builders |
| 42110 | Construction of roads and motorways | 5,010 | 42.11, 43.50 | Civil engineering: roads |
| 42990 | Construction of other civil engineering projects n.e.c. | 19,658 | 68.12, 42.99 | Civil engineering: catch-all |
| 43120 | Site preparation | 5,818 | 43.12 | Groundworks |
| 43210 | Electrical installation | 61,107 | 43.21 | Electricians |
| 43220 | Plumbing, heat and air-conditioning installation | 54,259 | 43.22 | Plumbers, heating, air conditioning |
| 43320 | Joinery installation | 24,576 | 43.32 | Joiners |
| 43341 | Painting | 18,358 | 43.34/1 | Painters |
| 43910 | Roofing activities | 19,298 | 43.41 | Roofers |
| 43999 | Other specialised construction activities n.e.c. | 69,143 | 10 possible codes | Catch-all for specialist trades |
Every Construction SIC Code
This table lists every code in Divisions 41, 42 and 43.
| SIC code | Companies House description | Active companies | SIC 2026 code |
|---|---|---|---|
| 41100 | Development of building projects | 116,907 | 68.12 |
| 41201 | Construction of commercial buildings | 44,810 | 41.01, 43.99, 91.30 |
| 41202 | Construction of domestic buildings | 103,580 | 41.02, 43.99, 91.30 |
| 42110 | Construction of roads and motorways | 5,010 | 42.11, 43.50 |
| 42120 | Construction of railways and underground railways | 3,786 | 42.12 |
| 42130 | Construction of bridges and tunnels | 554 | 42.13 |
| 42210 | Construction of utility projects for fluids | 1,194 | 42.21 |
| 42220 | Construction of utility projects for electricity and telecommunications | 5,229 | 42.22 |
| 42910 | Construction of water projects | 1,598 | 42.91 |
| 42990 | Construction of other civil engineering projects n.e.c. | 19,658 | 68.12, 42.99 |
| 43110 | Demolition | 2,361 | 43.11 |
| 43120 | Site preparation | 5,818 | 43.12 |
| 43130 | Test drilling and boring | 620 | 43.13 |
| 43210 | Electrical installation | 61,107 | 43.21 |
| 43220 | Plumbing, heat and air-conditioning installation | 54,259 | 43.22 |
| 43290 | Other construction installation | 41,162 | 43.23, 43.24 |
| 43310 | Plastering | 10,115 | 43.31 |
| 43320 | Joinery installation | 24,576 | 43.32 |
| 43330 | Floor and wall covering | 12,849 | 43.33 |
| 43341 | Painting | 18,358 | 43.34/1 |
| 43342 | Glazing | 8,273 | 43.34/2 |
| 43390 | Other building completion and finishing | 61,195 | 7 possible codes |
| 43910 | Roofing activities | 19,298 | 43.41 |
| 43991 | Scaffold erection | 7,380 | 43.99/1 |
| 43999 | Other specialised construction activities n.e.c. | 69,143 | 10 possible codes |
Who Construction SIC Codes Leave Out
- Sole traders. They are not on the Companies House register, and many tradespeople work this way. Ask any supplier whether its list includes them, including for our own plumbers data and electrical contractors data.
- Firms using another code. A construction firm may list a property or holding company code.
- Sites. Registered offices are not sites, so a SIC search will not show you where work is happening.
The contact rules differ too. The ICO guidance on email marketing says you can email corporate bodies, but sole traders and some partnerships are treated as individuals. Therefore you need specific consent, or the soft opt-in for past customers, before you email them. Check phone numbers against the TPS and CTPS as well.
Construction SIC Codes Under SIC 2026
The Office for National Statistics finalised UK SIC 2026 in April 2026, and several construction codes change.
| SIC 2007 code | Activity | Under SIC 2026 |
|---|---|---|
| 41.10 | Development of building projects | Moves to 68.12, outside construction |
| 41.20/1 | Construction of commercial buildings | Could go to 41.01, 43.99 or 91.30 |
| 41.20/2 | Construction of domestic buildings | Could go to 41.02, 43.99 or 91.30 |
| 43.91 | Roofing activities | Moves to 43.41 |
| 43.29 | Other construction installation | Could go to 43.23 or 43.24 |
| 43.99/9 | Specialised construction n.e.c. | Could go to any of 10 codes |
Any filter built on older construction SIC codes is therefore worth rechecking. You can read more in our UK SIC 2026 research.
How to Build a Construction List
- Pick your customer type. Match it to construction SIC codes using the first table in this guide.
- Add size. Staff numbers separate a national contractor from a two-person firm.
- Add region. It matters if you deliver or work on site.
- Choose job roles. A site manager, a contracts manager and a buyer can need different messages.
- Test a sample. Check it against firms you already know.
Our databases at the time of writing include 20,609 building contractors, 11,290 electrical contractors, 19,507 plumbers and 5,133 builders merchants. See all our UK industry databases. If you are ready to start outreach, see our lead generation targeting UK builders.
How We Checked This
Company counts come from Companies House advanced search, using the active status filter and one code at a time, on 5 November 2026. Descriptions come from the Companies House SIC code list. SIC 2026 codes come from the ONS correspondence table, dated 3 August 2026. A correspondence shows where a code could go. It does not tell you how any one company will be recoded. Our database figures are a separate source and count contacts, so they will not match company counts.
Frequently Asked Questions
What is the SIC code for a construction company?
Use 41201 for commercial buildings and 41202 for domestic buildings. Civil engineering is in Division 42, and specialist trades such as electrical, plumbing and roofing are in Division 43.
What is the SIC code for a builder?
A general builder would normally use 41202 for domestic work or 41201 for commercial work. Some firms use 43999 instead, so check it as well.
What is the SIC code for a property developer?
On the Companies House list, it is 41100, development of building projects. Under SIC 2026, this moves to 68.12, which sits outside the construction section.
What is the SIC code for an electrician or plumber?
Electrical installation is 43210. Plumbing, heating and air-conditioning installation is 43220.
Why are sole trader builders missing from SIC searches?
Companies House only holds registered companies and similar bodies. Sole traders are not on it, so you need another data source to reach them. Email rules are also stricter for them, so check ICO guidance.
RD Marketing Services That Can Help
Once you know which codes and audiences you need, these pages explain how we can help you reach them.
- Business lists UK: who we are and what we supply.
- Buy B2B data: our main page for buying UK business data.
- Email marketing databases: business email data for your campaigns.
- Buy telemarketing list: phone data for outbound sales teams.
- Marketing mailing lists: postal data for letters and mailshots.
- LinkedIn automation: managed outreach to decision-makers on LinkedIn.
- Automated email campaigns: email campaigns run and followed up for you.
Talk to Us
Need to reach the construction sector? Tell us who you want to reach, and we will send you a free audience count and quote within 24 hours, along with a sample.
Contact RD Marketing today to discuss your target market.