Formation
Companies House Authentication Code: How to Get or Recover It
Find out how to get, recover or change your Companies House authentication code, keep it safe and understand how it differs from your personal code.
Can a limited company have more than one SIC code?
Can a company have multiple SIC codes? Learn when to use more than one, how to cover different business activities and how to update your codes.
By Callum Sommerton30 October 20264 min read
Yes. A limited company can have up to four SIC codes to describe its business activities. You do not need to use all four: one is enough if it accurately describes what the company does.
The question becomes more useful when your business has several distinct activities. Perhaps you provide consultancy and build software, or run a shop alongside a separate service business.
Here’s how to decide whether another code helps, and how to update the record when the business changes.
When should you use more than one code?
Use additional codes where they describe distinct activities carried on by the company. Companies House confirms the four-code limit in its guidance on choosing a SIC code.
Start by writing down what customers actually buy from you. Separate the things you sell from the tasks you do internally to run the business.
For example, every business markets itself and keeps records. That does not mean every company needs codes for advertising and accounting services.
Situation | What to consider |
|---|---|
You provide one service under several package names | Those packages may fit a single activity |
You sell two distinct services | Check whether one code covers both or whether separate codes describe them more accurately |
You use software to deliver consultancy | Using software is different from selling software as a business activity |
You have an idea for a future service | Revisit the codes when the plans become a genuine business activity |
These are decision prompts, not automatic classifications. Read the descriptions for the activities concerned.
An example: consultancy and software development
Imagine a company that advises clients on IT systems and also develops bespoke software for them.
Two entries on the Companies House condensed SIC list are:
Code
Official description
62020
Information technology consultancy activities
62012
Business and domestic software development
Both might be relevant if the company genuinely provides both activities. A company that only gives advice should not add a development code simply because it uses software during its work.
The point is to explain the company’s activities accurately, rather than fill every available slot.
How do you choose the right combination?
Describe each activity in plain English. “We advise businesses on IT and build bespoke software” is easier to classify than a broad marketing slogan.
Search the official descriptions. Companies House requires codes from its condensed list.
Check for overlap. Two similar descriptions may be alternatives rather than a reason to select both.
Keep the smallest accurate set. Add another code where it explains an activity the existing selection misses.
You can use the free FOUNDRS SIC Code Finder to describe your business and explore suggested codes. Read the descriptions before deciding, particularly where your business combines different services.
For the broader process, see SIC codes explained: how to choose and update yours.
What if your company starts doing something new?
Review your current codes when the activities change. You might keep an existing code and add another, or remove a code for something the company no longer does.
SIC codes are updated through a confirmation statement. You can use the next statement, or file early if you need the record updated sooner. An early statement changes the review cycle, so check the resulting dates rather than relying on your old reminder.
Read our confirmation statement guide before filing. The official CS01 guidance identifies business activities as information that can be updated with the statement.
Do several activities mean you need several companies?
The number of SIC codes does not decide how many companies you should have. Codes describe activities; they do not create separate legal entities or separate the liabilities of one activity from another.
If you are considering a separate company, ask what you want to separate: ownership, commercial risk, investment or a future sale. Those questions deserve advice on the structure, rather than simply adding another code.
Likewise, a SIC code is not a licence or regulatory permission. Check the requirements for the activity itself before offering a new service.
Keep your company information useful
When you review your company details, ask whether a customer or supplier looking at the register would recognise the business you run today.
FOUNDRS helps founders organise company information and track recurring administration, including confirmation statements. Start with the SIC Code Finder, then explore the Compliance Assistant for ongoing company admin.
