Data Guide · 30 January 2026 · 8 min read

SIC Codes Explained: A Complete Guide for UK Businesses

If you've ever incorporated a company in the UK, you'll have encountered SIC codes — those cryptic five-digit numbers you had to choose during the registration process. But what are they actually for? How do they work? And why should you care about them?

Whether you're a company director choosing the right code for your business, a data analyst researching industry trends, or a salesperson using SIC codes to target prospects, this guide covers everything you need to know.

731

individual SIC codes in the UK classification system (SIC 2007)

What are SIC codes?

SIC stands for Standard Industrial Classification. SIC codes are a system for classifying business activities using numerical codes. Every company registered at Companies House must declare at least one SIC code that describes its primary business activity.

The UK currently uses the SIC 2007 system, which was introduced in January 2008. It's based on the European Union's NACE Rev. 2 classification and the United Nations' ISIC Rev. 4, making it broadly comparable with classification systems used internationally.

The structure of SIC codes

SIC codes follow a hierarchical structure with four levels:

Section (letter)21 sections: A through U

Division (2 digits)88 divisions

Group (3 digits)272 groups

Class (4 digits)615 classes

Subclass (5 digits)731 subclasses

For example, a web design agency might use SIC code 62012 — "Business and domestic software development". Breaking this down:

Section J — Information and communication
Division 62 — Computer programming, consultancy and related activities
Group 62.0 — Computer programming, consultancy and related activities
Class 62.01 — Computer programming activities
Subclass 62012 — Business and domestic software development

The complete section breakdown (A-U)

Here are all 21 sections of the UK SIC 2007 system, with brief descriptions and examples of the types of companies you'll find in each:

A — Agriculture, forestry & fishingFarms, forestry, fishing

B — Mining & quarryingOil, gas, mineral extraction

C — ManufacturingFactories, food production

D — Electricity, gas & air conEnergy generation, utilities

E — Water supply & wasteWater treatment, recycling

F — ConstructionBuilders, electricians, plumbers

G — Wholesale & retail tradeShops, e-commerce, wholesalers

H — Transportation & storageHaulage, courier, warehousing

I — Accommodation & foodHotels, restaurants, cafes

J — Information & communicationSoftware, telecoms, media

K — Financial & insuranceBanks, brokers, fintech

L — Real estateLettings, estate agents, SPVs

M — Professional & scientificConsultants, architects, legal

N — Administrative & supportRecruitment, cleaning, security

O — Public admin & defenceGovernment bodies

P — EducationSchools, training, tutoring

Q — Health & social workClinics, care homes, NHS

R — Arts, entertainment & recGyms, theatres, sports

S — Other service activitiesSalons, repairs, membership orgs

T — Households as employersDomestic staff employment

U — Extraterritorial organisationsEmbassies, international orgs

The most common SIC codes for new companies

Based on our analysis of new company incorporations at NewCo Data, the most frequently used SIC codes are:

47110 — Retail (non-specialised, food)~8% of new companies

68209 — Letting of own property~7%

70229 — Management consultancy~5%

43999 — Construction (other)~4%

56101 — Licensed restaurants~3%

62012 — Software development~3%

96090 — Other personal services~3%

74909 — Other professional activities~2%

The high proportion of retail (47110) reflects the ease of starting an online shop or marketplace business. Property letting (68209) remains popular despite recent regulatory changes, driven by the tax advantages of holding buy-to-let properties in a limited company.

How to choose the right SIC code

When incorporating a company, you must select at least one SIC code. Here's how to choose correctly:

Search the official list. Companies House provides a condensed list of SIC codes that you can search by keyword.
Be specific. Choose the most specific code that matches your business activity. Using a vague catch-all like "74909 — Other professional activities" when a more precise code exists is common but unhelpful.
Use multiple codes. If your business has multiple activities, you can (and should) declare several SIC codes. The primary code should be listed first.
Review regularly. If your business activities change, you can update your SIC codes via your annual Confirmation Statement.

It's worth noting that there's no penalty for choosing an "incorrect" SIC code. Companies House doesn't validate your choice against your actual business activities. However, choosing accurately is in your interest — it affects how your company appears in industry searches and classifications.

Why SIC codes matter for lead generation

For anyone involved in B2B sales or marketing, SIC codes are incredibly valuable because they're the primary public method for identifying what a company does.

If you're an insurance broker specialising in construction, you can filter for all new companies with SIC codes in divisions 41-43 (construction). If you're an accountant targeting IT firms, you'd look at division 62 (computer programming and consultancy). If you sell catering equipment, SIC codes 56101-56302 (food service activities) are your target.

This level of targeting is only possible because of SIC codes. Without them, you'd need to read every company name and try to guess what they do — which is impractical at the scale of 2,500+ new companies per day.

Limitations of SIC codes for targeting

While SIC codes are the best available tool for industry classification, they have limitations:

Self-declared and sometimes inaccurate. Directors choose their own codes, and many pick the wrong one or choose a generic catch-all.
Outdated classification system. SIC 2007 is nearly two decades old and doesn't perfectly capture modern business models. There's no specific code for "social media marketing agency" or "cryptocurrency exchange," for example.
Single classification only. A company that does both web design and marketing might only declare one SIC code, meaning they'd be invisible in searches for the other.
No granularity within codes. SIC code 62012 covers everything from a one-person WordPress developer to a large enterprise software company.

Despite these limitations, SIC codes remain by far the best publicly available method for classifying UK businesses by industry. Services like NewCo Data use SIC codes as the primary filtering mechanism for delivering sector-specific new company reports.

SIC codes and market research

Beyond lead generation, SIC codes are essential for market research. By tracking incorporation volumes by SIC code over time, you can identify growing sectors (more new companies forming), declining sectors (fewer formations), and seasonal patterns within specific industries.

Government statistics, ONS data, and economic reports all use SIC classifications. Understanding the system lets you cross-reference Companies House data with broader economic datasets to build a comprehensive picture of market conditions.

Filter new companies by SIC code — delivered daily

NewCo Data uses SIC codes to deliver sector-specific reports of newly incorporated UK companies. Choose your target industries and get daily leads with director names and addresses.

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Key takeaways

SIC codes are the UK's system for classifying business activities, using a five-digit hierarchical structure. There are 731 individual codes across 21 sections (A-U). Every Companies House registered company must declare at least one SIC code. They're self-declared and sometimes inaccurate, but remain the best public classification tool available. For lead generation, SIC codes enable precise industry targeting of new company data. NewCo Data uses SIC codes to filter daily incorporation reports by sector, letting you target exactly the industries you serve.