Other specialised construction activities n.e.c. (SIC code 43999)
Other specialised construction activities n.e.c. is UK SIC code 43999. It sits in division 43 (Specialised construction activities) of the SIC 2007 list. On the August 2026 Companies House register, 62,240 active UK companies list 43999 among their SIC codes. 47,320 of them list it first. That makes it the most used code in its division.
62,240active UK companies list SIC 43999 among their codes on the public recordCompanies House · counts as of August 2026
SIC 43999 in numbers
62,240 companies is 1.2 per cent of the 5,190,464 active companies on the UK register. 43999 is the most used of the 15 codes we track in division 43.
47,320 put 43999 first and 14,920, 24 per cent, list it in one of their other three slots. First code only gives the tighter list; any position gives more of them.
ACTIVE COMPANIES BY REGISTERED-OFFICE POST TOWN (WHERE THE PAPERWORK SITS, NOT NECESSARILY THE WORK) · COMPANIES HOUSE PUBLIC RECORD, AUGUST 2026
London is the largest cluster at 13 per cent and the top five post towns hold 18 per cent, so the other 82 per cent sit across the rest of the country. A regional filter narrows the list without gutting it.
A worked example: 43999, registered office in London, incorporated in the last ninety days, from a pool of 62,240. Each lead you get arrives with a working website and a real email, and the director's name when the record has one. If we cannot complete one, you pay nothing.
SIC 43999 companies, as leads
Live rows from the enriched public record. Email addresses are withheld until you sign up. Phone numbers come with paid plans.
Tradesmen (all) in one town or city
Choose a place and see 3 of them there, before you sign up.
Tell us who you sell to. We find them, with a real email. 100 free leads, no card.
This is the trades division, and one of the biggest classifications on the UK register.
Related SIC codes
How to read SIC 43999
SIC 43999 reads as division 43 (specialised construction activities), group 439, class 4399, then the full five digits, inside section F, construction. A company picks its own codes, up to four, and Companies House does not check them, so 43999 is the company's own description of what it does, and 47,320 list it first where 62,240 list it anywhere.
Who sells into division 43
Lots of firms sell to the trades, because their needs are predictable and repeat every year. They buy public liability insurance, accountancy for CIS refunds and company compliance, van leasing, tools and trade credit from merchants.
About SIC 43999
How many UK companies use SIC code 43999?
62,240 active UK companies list 43999 (Other specialised construction activities n.e.c.) among their registered SIC codes. Each company may register up to four. Of those, 47,320 put it first. The figures come from the August 2026 Companies House register snapshot, and count active companies only.
Should a multi-trade builder use 43999 or a specific trade code?
If one trade brings in most of your income, use its own code. That means 43210 for electrical work or 43220 for plumbing and heating. Specific codes read better to insurers and merchants. Genuinely multi-skilled firms use 43999 or 43390, or list up to four codes covering their main trades. The choice is yours. Companies House records it without judgement, and you can change it on any confirmation statement.
Find UK SIC 43999 companies
Filter Companies House by this code. Each lead arrives with a working website and a real email, or you pay nothing. 100 free leads, no card.
✓ No card · ✓ 100 free leads · ✓ Nothing to cancel