The Complete Guide to SIC Codes for UK B2B Lead Generation

SIC codes are how the UK government classifies every business in the country. They are also the single most useful filter in B2B prospecting, far more powerful than industry tags from third-party data tools, because every UK Ltd company *self-declares* its SIC codes when it incorporates and updates them in every confirmation statement.

This guide covers what they are, how they are structured, the most commercially valuable ones in 2026, and the common mistakes new prospectors make.

What is a SIC code?

SIC stands for Standard Industrial Classification. The current UK version is SIC 2007, a five-digit hierarchical code that groups every type of economic activity into ~730 categories.

Every UK limited company picks between 1 and 4 SIC codes when it incorporates. Sole traders and partnerships don't have them, but anyone trading through a Ltd company does, and the codes are public via Companies House.

The SIC 2007 structure

The codes are organised top-down:

• Section (1 letter, A–U), the broadest grouping. There are 21 sections, e.g. F (Construction), J (Information and Communication), K (Financial and Insurance Activities).
• Division (2 digits), narrows it. Section J contains divisions 58 (Publishing), 59 (Motion picture, video and TV), 60 (Programming and broadcasting), 61 (Telecommunications), 62 (Computer programming and consultancy), 63 (Information service activities).
• Group (3 digits), narrower again. 62.0 = Computer programming, consultancy and related activities.
• Class (4 digits), narrower again. 62.01 = Computer programming activities.
• Subclass (5 digits), the leaf level. 62012 = Business and domestic software development. 62011 = Ready-made interactive leisure and entertainment software development.

When you filter prospects by SIC code, you almost always work at the 5-digit subclass level for the highest precision, but cluster multiple subclasses together to avoid missing close matches (see our recently-incorporated guide for examples).

The most valuable SIC codes by sector

These are the SIC clusters our customers most frequently use as the starting point for high-intent prospect lists.

Professional services (sell to founders, finance teams)

• 69201, Accounting and auditing activities
• 69202, Bookkeeping activities
• 69109, Activities of solicitors n.e.c.
• 70210, Public relations and communications activities
• 70229, Management consultancy activities other than financial management

Marketing, advertising, creative

• 73110, Advertising agencies
• 73120, Media representation services
• 74100, Specialised design activities
• 74201, Portrait photographic activities
• 74202, Other specialist photography
• 59112, Video production activities

Construction and trades

• 41201, Construction of commercial buildings
• 41202, Construction of domestic buildings
• 43210, Electrical installation
• 43220, Plumbing, heat and air-conditioning installation
• 43330, Floor and wall covering
• 43342, Painting
• 43390, Other building completion and finishing

IT, software, hosting

• 62012, Business and domestic software development
• 62020, Computer consultancy activities
• 62090, Other information technology service activities
• 63110, Data processing, hosting and related activities
• 63120, Web portals

Hospitality and food service

• 56101, Licensed restaurants
• 56102, Unlicensed restaurants and cafés
• 56210, Event catering activities
• 55209, Other holiday and other collective accommodation
• 56301, Licensed clubs

Retail and e-commerce

• 47910, Retail sale via mail order houses or via internet
• 47990, Other retail sale not in stores, stalls or markets
• 47710, Retail sale of clothing in specialised stores

Transport and logistics

• 49410, Freight transport by road
• 53201, Licensed carriers
• 52290, Other transportation support activities

Health, beauty, fitness

• 86230, Dental practice activities
• 86900, Other human health activities
• 96020, Hairdressing and other beauty treatment
• 93130, Fitness facilities

Common mistakes

Mistake 1: Filtering on a single SIC code. Most companies pick the first plausible code they see in the dropdown. A web agency might be 73110, 62020, 70229 or 74100, all four are reasonable. Cluster.

Mistake 2: Trusting the SIC code as ground truth. SIC codes are self-declared at incorporation and rarely updated. A company that was a "management consultancy" five years ago might now be a SaaS business. Use SIC as a *first-pass filter*, not as the only filter.

Mistake 3: Ignoring the "n.e.c." codes. "Not elsewhere classified" subclasses (e.g. 70229, 96090) are sweepingly broad and contain a lot of high-value targets that none of the more specific codes would match.

Mistake 4: Filtering only on UK companies. SIC codes are unique to the UK and Republic of Ireland (which uses NACE Rev 2, broadly compatible). Do not try to use them for international targeting; switch to NAICS (US) or ISIC (international) instead.

How to use SIC codes inside Leadistry

Inside Leadistry's search builder, you can either type the SIC code directly, browse the full SIC tree, or pick a pre-built template that bundles a curated cluster (e.g. "Construction & trades", "Insurance broker prospects", "Brand-new businesses"). Every template combines a SIC cluster with a sensible incorporation-date window and the recommended enrichment fields.

For most users, starting from a template and tweaking is faster than building from scratch.

Bottom line

SIC codes are not glamorous, but they are the backbone of every serious UK B2B prospecting workflow. Spend an hour mapping your ICP to a 4–8 code cluster and you will get more targeting precision than any number of vendor-supplied "industry tags".