When a company is incorporated in the UK, the application must state what it intends to do. It does so with up to four codes from the UK Standard Industrial Classification of Economic Activities 2007, known as SIC 2007. Each is a five-digit code with a short description, such as 62012 for business and domestic software development or 43210 for electrical installation. Companies House stores them on the public record, and they are the closest thing a brand-new company has to a description of itself.
How the codes are structured
SIC 2007 is hierarchical. The first two digits are the division, a broad sector such as 62 for computer programming and consultancy or 41 for construction of buildings. The next digits narrow to group, class and finally the UK-specific five-digit subclass. That hierarchy is what makes SIC codes filterable: a search for every division-62 code catches all software and IT services companies without listing each subclass.
Companies House publishes a condensed list of about 730 codes that companies may choose from. Two are special: 99999 means a dormant company and 74990 means a non-trading company. A company filing either is telling you it is not open for business yet, which is itself a signal.
The codes new companies choose most
| Code | Description | What it usually means |
|---|---|---|
| 62012 | Business and domestic software development | Software studios, SaaS start-ups, app developers |
| 62020 | Information technology consultancy activities | IT contractors, consultancies, freelance developers |
| 70229 | Management consultancy activities other than financial management | Consultants of every kind; the register's most common catch-all |
| 82990 | Other business support service activities n.e.c. | Virtual assistants, agencies and anything that did not fit elsewhere |
| 47910 | Retail sale via mail order houses or via Internet | E-commerce and marketplace sellers |
| 68209 | Other letting and operating of own or leased real estate | Buy-to-let and property-holding vehicles |
| 41202 | Construction of domestic buildings | House builders and developers |
| 43390 | Other building completion and finishing | Trades: decorators, fitters, finishers |
| 56103 | Take-away food shops and mobile food stands | Food businesses and delivery kitchens |
| 96090 | Other service activities n.e.c. | Personal services, and a frequent default |
Using SIC codes for lead filtering
Because the codes are hierarchical and machine-readable, they are the fastest way to cut a week of incorporations down to the companies you can help. Lead Forge groups the first code on each record into broad categories in the directory, and reads all of them on the profile with plain-English descriptions. The Companies House advanced search accepts a list of codes directly. Three practical rules:
- Filter on divisions, not subclasses. Founders pick codes quickly and inconsistently. A software company might file 62012, 62020, 62090 or 63110. Catching the whole division is more reliable than any one code.
- Read all the codes, not just the first. The order is not meaningful. A company filing 70229 and 62020 is probably an IT consultancy that hedged.
- Treat catch-alls as unknowns. 70229, 82990 and 96090 tell you very little. The company name, the director's occupation on the appointment record and the registered office tell you more.
What SIC codes cannot tell you
They are not verified. Nobody at Companies House checks that a company filing 62012 writes software. They describe intent at the moment of incorporation and are often never updated. They say nothing about size, revenue, customers or whether the company has started trading. This is why Lead Forge's AI analysis labels any inference from a SIC code as interpretation rather than fact, and why the first question on a call should always be 'what do you actually do?'
QUICK ANSWERS
Questions this article answers
- How many SIC codes can a UK company have?
- Up to four. Most new companies file one or two. Codes can be changed later on the confirmation statement.
- Are SIC codes verified by Companies House?
- No. A SIC code is chosen by the person filing the incorporation and describes intended activity. It is a useful signal, not a confirmation of what the company sells.