A SIC code (Standard Industrial Classification code) is a 5-digit number that classifies a company’s principal business activity. Every UK company must provide at least one SIC code when it is incorporated at Companies House, and confirm it each year through the confirmation statement.
What Are SIC Codes Used For?
| Purpose | Detail |
|---|---|
| Companies House | Classifies companies by industry on the public register |
| HMRC | Uses SIC codes for tax administration and risk profiling |
| ONS (Office for National Statistics) | Compiles economic statistics by industry sector |
| Government policy | Identifies sectors for targeted support, grants and regulation |
| Credit reference agencies | Assesses industry risk when scoring businesses |
| Investors and lenders | Understands the nature of the business at a glance |
SIC Code Structure
The UK uses the SIC 2007 classification system (based on the EU’s NACE Rev. 2). Codes are organised hierarchically:
| Level | Example | Description |
|---|---|---|
| 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 | 62011 | Ready-made interactive leisure and entertainment software development |
Companies House requires the 5-digit subclass code.
Common SIC Codes
| SIC Code | Description |
|---|---|
| 62020 | Information technology consultancy activities |
| 70229 | Management consultancy activities other than financial management |
| 47910 | Retail sale via mail order houses or via internet |
| 41100 | Development of building projects |
| 56101 | Licensed restaurants |
| 69201 | Bookkeeping activities |
| 69202 | Accounting and auditing activities |
| 82990 | Other business support service activities |
| 96090 | Other personal service activities |
| 68100 | Buying and selling of own real estate |
| 68209 | Other letting and operating of own or leased real estate |
| 64209 | Activities of other holding companies |
How to Choose the Right SIC Code
Step 1: Identify the Principal Activity
The SIC code should represent the company’s main business activity — the activity that generates the most revenue or is the primary purpose of the company. If the company has multiple activities, choose the code that best represents the principal one.
Step 2: Search the SIC Code List
Companies House provides a searchable tool and a downloadable list of all valid SIC codes. The full list is available in the UK SIC 2007 condensed classification published by the ONS.
Step 3: Be Specific
Choose the most specific code that matches the activity. A general code should only be used when no specific code exists.
| Instead of | Use |
|---|---|
| 82990 (Other business support) | 70229 (Management consultancy) if that is the actual activity |
| 47190 (Other retail sale) | 47910 (Retail via internet) if the business is an online retailer |
| 96090 (Other personal services) | The specific personal service code if one exists |
Step 4: Multiple Codes
A company can provide up to 4 SIC codes on the confirmation statement, allowing it to describe multiple activities. The first code listed should be the principal activity.
When to Provide a SIC Code
| Event | Action |
|---|---|
| Incorporation | At least one SIC code on form IN01 |
| Annual confirmation statement | Confirm or update the SIC code(s) |
| Change of principal activity | Update at the next confirmation statement |
| HMRC registration | Provide the SIC code when registering for corporation tax |
Changing the SIC Code
If the company’s business activity changes, the SIC code should be updated at the next confirmation statement filing. There is no separate form to change the SIC code — it is simply updated when filing the CS01.
A change of SIC code does not require a special resolution or amendment to the articles of association (unless the articles restrict the company’s permitted activities).
SIC Codes for Holding and Dormant Companies
| Company Type | Typical SIC Code |
|---|---|
| Holding company (owns shares in subsidiaries) | 64209 — Activities of other holding companies |
| Dormant company | 99999 — Dormant company |
| Property holding | 68209 — Letting and operating of own or leased real estate |
Companies that have not yet started trading may use code 74990 (Non-trading company) or the code for their intended activity.
SIC Codes and HMRC
HMRC uses SIC codes to:
- Classify companies for tax compliance monitoring
- Identify companies in high-risk sectors for enquiry
- Compare a company’s declared income with industry norms
- Determine eligibility for certain tax reliefs (e.g. R&D tax credits, creative industry reliefs)
An incorrect SIC code will not directly cause a penalty, but it could lead to unnecessary scrutiny if HMRC’s automated systems flag the company based on sector benchmarks.
Common Mistakes
| Mistake | Problem |
|---|---|
| Using a code that is too general | Does not accurately describe the business; may trigger HMRC queries |
| Using the wrong code entirely | Companies House record does not match actual activity |
| Not updating after a business pivot | Public register shows outdated information |
| Confusing SIC codes with other classifications | SIC codes are specific to Companies House / ONS; other schemes (e.g. HMRC trade classifications) are different |
| Using a 4-digit code | Companies House requires the full 5-digit code |