SIC codes are one of the first choices you make when you form a company and one of the easiest to neglect afterwards. They sit on the public register, they are confirmed in every confirmation statement and they are read by banks, insurers, lenders, investors and compliance teams. This guide explains everything a director needs to know about SIC codes in one place, with links to deeper articles on each topic.
1. What is a SIC code?
SIC stands for Standard Industrial Classification. The UK uses SIC 2007, a list of five-digit codes grouped by economic activity. Companies House asks every company to list at least one and up to four codes describing the nature of its business. The codes are used for statistics and by organisations that classify companies. They are not licences and do not restrict what you may do. Our article what is a SIC code gives a plain-English introduction.
2. Why they matter
A SIC code is a public statement about your business. A mismatch between your code and your invoices, website or accounts can raise questions during bank onboarding, insurance applications, lending decisions and due diligence. Property lenders often require a specific letting code. Marketplaces and payment providers compare codes with your products. Accurate codes make these processes smoother and show that the company is properly maintained.
3. How many can you have?
You must have at least one and can have up to four. The first is treated as the main activity. Use as many as you need to describe genuine, significant activities and no more. One accurate code is better than four loosely related ones. See how many SIC codes a company can have.
4. Choosing the right code
Start by describing how the company makes money. Search the Companies House list using keywords, read the full descriptions and choose the most specific match for your main income. Add secondary codes only for real activities. Use catch-all codes only when nothing more precise exists. Our step-by-step method is in how to choose the right SIC code, and the discussion of vague codes is in SIC code 82990 and other catch-all codes.
5. Examples by sector
Different sectors have their own typical codes. Consultants and freelancers often use management consultancy or IT consultancy codes. Online retailers commonly use 47910. Landlords use 68209, developers 41100 or 68100, and holding companies 64209. Builders and tradespeople have a long list of 43 codes for each trade. Restaurants use 56101, 56102 or 56103 depending on licensing and model. Software firms use 62012 and related codes. Read our guides for consultants and freelancers, ecommerce, property, construction, software and hospitality.
6. Changing your codes
You can change your SIC codes whenever your activities change, normally through your confirmation statement. File early in the review period if you cannot wait. There is no separate fee for the change itself beyond the filing fee. Update your insurer and bank if the change is material. Our guide how to change your SIC code at Companies House walks through the steps, and our SIC code change service for London companies can do it for you with a quote before work starts.
7. SIC codes, tax and HMRC
SIC codes do not determine your tax. HMRC looks at the facts. But HMRC and others do see the codes, and inconsistencies can attract questions. Reliefs such as R&D tax credits depend on what you do, not on the code. Choosing a code to gain a benefit you are not entitled to is misrepresentation. See do SIC codes affect tax or HMRC.
8. What if your code is wrong?
A wrong or outdated code is very common. It is not usually prosecuted but it creates friction and, if knowingly false, can be an offence. Fix it at the next confirmation statement. Read wrong SIC code: what happens and how to fix it.
9. Holding companies and groups
Holding companies use holding codes, ideally matching the sector of the subsidiaries, and each company in a group has its own code. Lenders check the entity that owns the asset. See SIC codes for holding companies and group structures.
10. A yearly review habit
Each year, when you prepare your confirmation statement, compare your codes with your accounts, invoices and website. If the business has shifted, update. If you added a new line, add a code. If an old line has stopped, remove it. The review takes a few minutes and keeps the public record accurate.
Summary
Choose specific codes, keep them honest, review each year and update when things change. If you want help, our team can review your codes and file the change.
Worked example of a code review
A London design agency incorporated with 74100 for specialised design activities. Over five years it added web development and an online template shop. At review time the directors rank income: web development 50%, design 35%, templates 15%. They update the codes to 62012 first, 74100 second and 47910 third. The register now reflects the business, and when the agency applies for a merchant account the bank sees a profile that matches the website.
Mistakes to avoid, summarised
Do not copy a competitor’s codes without reading the descriptions. Do not leave a placeholder from a formation agent. Do not add codes for work you might do in future. Do not choose a code to look bigger or to qualify for a scheme. Do not forget to tell insurers about material changes. Do review codes annually and keep them in line with your documents.
When to ask for help
If your activities are mixed, unusual or regulated, a short conversation with an accountant is worth the time. We can recommend codes and file the change as part of a confirmation statement. Because rules and the SIC list can change, always check Companies House guidance before you file.
Frequently asked questions
What does SIC stand for?
Standard Industrial Classification.
Do SIC codes affect my tax?
No. Tax depends on the facts of your business, not the code.
How do I change my SIC code?
Update it in your confirmation statement through Companies House.
How many codes can I use?
Up to four, with the main activity first.
Related articles
- The Complete Guide to PSCs: People with Significant Control
- The Complete Guide to Director ID Verification in the UK
- The Complete Guide to Strike-Off, Dissolution and Company Restoration
- The UK company annual compliance calendar
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