What Are SIC Codes? The Complete Guide for UK Businesses

What Are SIC Codes?

SIC codes (Standard Industrial Classification codes) are five-digit numerical codes that categorise the type of economic activity a business undertakes. Every UK company must declare at least one SIC code when they register with Companies House.

The UK SIC system is based on the European NACE classification and is maintained by the Office for National Statistics (ONS). The current version, SIC 2007, contains approximately 730 individual codes organised into a hierarchical structure.

How SIC Codes Are Structured

SIC codes follow a hierarchical pattern that moves from broad industry sections down to very specific activity subclasses:

Level	Example	Description
Section	G	Wholesale and retail trade
Division	47	Retail trade
Group	47.1	Retail sale in non-specialised stores
Class	47.11	Retail sale with food, beverages or tobacco predominating
Subclass	47.11/1	Retail sale with food, beverages or tobacco predominating (large)

The five-digit code (e.g., 62012 for "Business and domestic software development") provides the most specific categorisation. When you search Companies House or use a tool like our SIC code lookup, you are always working with these five-digit subclass codes.

Common SIC Codes for Newly Registered UK Companies

The table below covers the SIC 2007 codes that appear most frequently among new company registrations, spanning technology, construction, professional services, and real estate. These are the codes you are most likely to encounter when monitoring newly formed businesses:

SIC Code	Description	Typical business type
62012	Business and domestic software development	Software studios, app developers, SaaS startups
62020	Information technology consultancy activities	IT consultants, technical project managers
70229	Management consultancy activities (other than financial management)	Strategy, operations, and HR consultants
69201	Accounting and auditing activities	Accountancy practices, bookkeepers
69202	Bookkeeping activities	Bookkeeping sole traders incorporated as limited companies
41100	Development of building projects	Property developers, residential and commercial build
43999	Other specialised construction activities not elsewhere classified	Specialist tradespeople, fit-out contractors
68100	Buying and selling of own real estate	Property investment vehicles
68209	Other letting and operating of own or leased real estate	Residential and commercial landlords
47910	Retail sale via mail order houses or via Internet	E-commerce businesses, Amazon sellers
74909	Other professional, scientific and technical activities not elsewhere classified	Niche specialists who do not fit a tighter code
82990	Other business support service activities not elsewhere classified	Business services companies, outsourcing firms
96090	Other service activities not elsewhere classified	Personal services and miscellaneous service businesses
74990	Non-trading company	Holding companies or dormant vehicles with some activity
99999	Dormant company	Companies with no significant accounting transactions

You can explore the full list of UK SIC 2007 codes - including parent sections and related codes - using our free SIC code lookup tool.

How to Find the Right SIC Code for Your Business

When registering a company, you need to choose the SIC code (or codes) that best describe your business activities. Here is how to approach the selection:

1. Browse the official list - The Companies House SIC code search lets you search by keyword.
2. Think about your primary activity - What does your business actually do, not what industry you consider yourself part of. A firm that builds software for logistics companies is a software developer (62012), not a logistics company.
3. Use multiple codes - You can declare up to four SIC codes to cover different aspects of your business (see the up-to-4-codes rule below).
4. Be specific - Choose the most specific code that matches, rather than a generic parent category. Specificity makes your filing more useful and avoids the catch-all codes (82990, 96090, 74909) that say very little about what a business does.
5. When nothing fits - If no code precisely describes your business, choose the closest match at the Class level and supplement it with a more descriptive second code.

The Up-to-4-Codes Rule at Companies House

UK companies can register up to four SIC codes on their Companies House record. This matters for businesses that operate across multiple sectors - for example, a firm that does both software development and IT consultancy could register 62012 and 62020 simultaneously. The codes appear in the order you enter them, and the first code is generally treated as the primary business activity.

There is no minimum number of codes required beyond one, and there is no formal ranking system - but as a practical convention, lead with the code that represents the majority of your revenue or activity.

How to Change or Update Your SIC Codes

Businesses change. A company that started as a consultant may pivot to become a software product company, or a contractor may add property investment to their activities. Fortunately, SIC codes are not fixed at incorporation.

You update your SIC codes through the annual confirmation statement (formerly the annual return), filed via the Companies House online service. The process is straightforward:

• Log in to the Companies House WebFiling service
• File or review your confirmation statement
• Update the SIC code section with new codes
• Submit - the change takes effect immediately and appears on your public record

There is no fee specifically for changing SIC codes; however, if you file the confirmation statement early in order to update them, you pay the standard confirmation statement fee (currently £34 online or £62 by paper).

Dormant and Non-Trading Companies

Two special-purpose SIC codes are worth knowing:

• 99999 - Dormant company: Used when a company has had no significant accounting transactions during the period. Shelf companies and SPVs set up for future use often carry this code.
• 74990 - Non-trading company: Used for companies that exist legally but are not currently trading - for example, holding companies that own shares in subsidiaries but do not trade directly. This is distinct from dormant; a holding company may have income (dividends from subsidiaries) but uses 74990 because it does not "trade" in the traditional sense.

When prospecting for new clients, filtering out 99999 and 74990 registrations often improves lead quality - these companies are unlikely to need your services immediately. NewcoHunter's search lets you exclude these codes so you only see actively trading new companies in your target sector.

Why SIC Codes Matter for Business

SIC codes are not just a regulatory requirement. They are a powerful tool for understanding markets and finding customers.

Market Research: SIC codes let you quantify the size of any industry in the UK. How many active companies operate in your sector? How many new ones are being formed each month? Which regions have the highest concentration? The ONS publishes annual business counts by SIC section that let you benchmark your market.

Lead Generation: For B2B companies, SIC codes are the most reliable way to identify potential customers by industry. Unlike self-reported categories on LinkedIn or Google, SIC codes are standardised and mandatory - every limited company has them. You can read more about how to use this data in our guide to new company data for B2B lead generation.

Competitive Analysis: By monitoring new registrations in your SIC code, you can track how many new competitors are entering your market and where they are setting up. A surge in new registrations under 62012 in a particular city might signal a growing local tech ecosystem - or increased competition for the same clients.

Government and Policy: SIC codes are used extensively in government statistics, grant eligibility criteria, and regulatory frameworks. The right SIC code can determine whether your business qualifies for certain tax reliefs or funding schemes. Some grant programmes, particularly for R&D or creative industries, specify eligible SIC codes in their criteria.

For a deeper understanding of how Companies House works and what data is available, our Companies House complete guide covers the full range of public filings and search options.

Using SIC Codes for B2B Prospecting

One of the most underused applications of SIC codes is identifying new potential clients at the exact moment they start trading. A company that has just been registered with SIC code 41100 (Development of building projects) is a brand-new property developer - and one that probably needs accountancy, insurance, legal, and a range of professional services for the first time.

This is the insight behind how NewcoHunter works: we monitor Companies House for new incorporations daily, index them by SIC code and geography, and surface them to service providers who want to reach new businesses before competitors do.

For B2B prospecting via SIC codes, the most effective approach is:

• Identify your best-fit SIC codes - Think about which industries your best existing clients come from and map them to SIC codes. If you serve IT contractors, you will likely want 62012 and 62020. If you serve construction businesses, 41100, 43999, and related codes are your targets.
• Layer in geography - Most service providers have a practical catchment area. Filtering by region or postcode prefix keeps your prospect list manageable and relevant.
• Filter by date of incorporation - New companies registered in the last 30 to 90 days are in the "new business" buying window. They are actively making supplier decisions and have not yet built supplier loyalty.
• Set up ongoing alerts - Rather than running one-off searches, set up a saved search to receive a weekly digest of new registrations matching your SIC codes. This turns a static list into a continuous pipeline.

You can see new company registrations by SIC code directly on NewcoHunter, filtered by industry and location, updated daily from Companies House data.

Using SIC Codes with NewcoHunter

NewcoHunter is built around SIC codes. Our platform lets you:

• Browse all SIC codes with descriptions and related categories via our SIC code lookup tool
• Search new companies by SIC code to find businesses in specific industries
• Combine SIC codes with location to find new companies in your target market and geography
• Set up alerts to receive weekly emails when new companies register with your chosen SIC codes

This makes NewcoHunter uniquely powerful for B2B sales teams, accountants, and business service providers who need to find potential clients by industry.

Browse SIC codes and find new companies

Frequently Asked Questions

How many SIC codes can a company have?

A UK company can register up to four SIC codes on its Companies House record. At least one is required when incorporating. Most companies use one or two codes. If your business operates across clearly distinct sectors, using multiple codes makes your public record more accurate and makes you easier to find by people researching companies in those industries.

Can I change my SIC code after incorporation?

Yes. SIC codes can be updated at any time through the annual confirmation statement filed via Companies House WebFiling. There is no standalone process for changing SIC codes alone - you update them as part of the confirmation statement. The change appears on your public record immediately once submitted. If your business has pivoted or expanded since incorporation, it is worth reviewing your registered codes at the next confirmation statement.

What is SIC code 99999?

SIC code 99999 denotes a dormant company - one that has had no significant accounting transactions during the accounting period. Companies set up as shelf companies, special purpose vehicles, or holding structures that are not yet active typically use this code. It is distinct from 74990 (non-trading company), which is used for companies that exist and may have some financial activity (such as receiving dividends) but are not trading in their own right.

Do SIC codes affect tax or VAT treatment?

SIC codes themselves do not directly determine your tax treatment or VAT liability - those are governed by HMRC's own rules, which look at what you actually do rather than your Companies House classification. However, SIC codes can have indirect effects: some R&D tax credit claims, creative industry reliefs, and grant schemes specify eligible SIC codes in their terms. It is worth checking whether your SIC code aligns with any schemes your business might qualify for. If there is a mismatch between what you do and your registered SIC code, it is worth updating it at your next confirmation statement.

How do I find a company's SIC code?

Every UK company's SIC codes are publicly available on the Companies House register. You can look up any company at find-and-update.company-information.service.gov.uk and the SIC codes appear on the company overview page. Alternatively, our SIC code lookup tool lets you search codes by keyword or number to find the right code for your own business, and you can then use those codes to search for newly registered companies in the same sector on NewcoHunter.