Changing your SIC code on Companies House is done by filing a confirmation statement online or by post.
If your business activities have changed, you selected the wrong code during company formation, or you now offer different services, updating your SIC code helps keep your company records accurate and compliant with UK regulations. You can either wait until your next confirmation statement is due or file one early if the change is urgent.
Key takeaways:
- SIC codes identify your company’s business activities
- UK companies can use up to 4 SIC codes
- Changes are made through a confirmation statement (CS01)
- You can file an early confirmation statement if needed
- Accurate SIC codes help with compliance, funding, and credibility
- Dormant and non-trading companies still need SIC codes
As Companies House explains, SIC codes help track economic activity across the UK and ensure public company records remain accurate and transparent.
What Is a SIC Code and Why Does It Matter for UK Companies?
A SIC code, or Standard Industrial Classification code, is a five-digit number used by Companies House to identify the type of business activities your company carries out. Every UK limited company must provide at least one SIC code when registering and maintain accurate codes as the business evolves.
These codes are important because they help government bodies, HMRC, lenders, investors, and insurers understand what your company does. SIC codes also support economic reporting and industry analysis across the UK economy.
If your company operates in several areas, you can choose up to four SIC codes to reflect your activities accurately. Even dormant or non-trading companies must still use a valid code.
Companies House previously explained this clearly by stating:
“There are over 600 individual SIC codes to choose from and you’ll need to provide at least one code to describe what your business does.”
Keeping your SIC code updated improves transparency and ensures your company information reflects your real operations.
Why Would You Need to Change Your SIC Code on Companies House?
Businesses change over time, and your SIC code should reflect your current activities accurately. If your company expands into new services, stops offering certain products, or moves into a completely different sector, your original SIC code may no longer be suitable.
Some businesses also realise they selected the wrong code during incorporation because the descriptions can be highly specific. Updating the code helps avoid confusion for regulators, lenders, suppliers, and customers reviewing your public company profile.
Common reasons for changing your SIC code include:
- Your business activities have changed significantly
- You added new products or services
- You stopped operating in a previous sector
- You chose an incorrect SIC code when forming the company
- You are applying for grants or tenders linked to industry classifications
- You want company records to reflect your actual operations
For example, a retail company that later moves into software development should update its SIC code to avoid outdated classifications remaining on public records.
A business adviser quoted in industry discussions explained:
“A UK business SIC code is just an indicator of the company’s business activity. If your company moves in a different direction from what you anticipated, that is absolutely fine – you simply need to update the code.”
This reassures business owners that changing SIC codes is a normal part of company growth and restructuring.
How Can You Change Your SIC Code on Companies House?
Changing your SIC code is relatively straightforward once you understand the process. In the UK, Companies House only allows SIC code updates through a confirmation statement. This ensures company information stays formally recorded and legally verified.
You can either wait until your annual confirmation statement is due or file an early confirmation statement if you need the changes reflected sooner.
How Do You Change Your SIC Code Using a Confirmation Statement?
To update your SIC code online, you will need access to the Companies House WebFiling service and your company authentication code.
The process usually involves:
- Logging into Companies House WebFiling
- Opening your confirmation statement (CS01)
- Reviewing your existing company details
- Replacing or adding SIC codes
- Submitting the confirmation statement
You can search the official SIC code list to find the most accurate classification for your business activities. Once Companies House accepts the filing, the updated SIC codes will appear on your public company profile.
Companies House guidance notes that keeping company records current is considered good business practice because it helps anyone researching your company access reliable information.
One Companies House blog statement highlighted this directly:
“It’s good practice to keep your information up-to-date so anyone looking to do business with your company has accurate information.”
That reflects why many businesses choose to review SIC codes regularly rather than waiting until major operational changes occur.
Can You File an Early Confirmation Statement to Change SIC Codes?
Yes, you can file a confirmation statement before the normal due date if you need to update your SIC code quickly. This is commonly known as an early confirmation statement.
Businesses often use this option when:
- Entering a new industry
- Applying for funding or investment
- Updating company branding or services
- Correcting an incorrect SIC code urgently
Online filings are generally processed faster than paper submissions. Filing early does not change your next confirmation statement date, but it allows Companies House records to reflect updated information sooner.
According to business guidance sources, filing fees currently apply for both online and postal submissions. Online filing is usually preferred because it is quicker, easier to track, and reduces administrative delays.
What Do You Need Before Updating Your SIC Code?
Before changing your SIC code, it is important to prepare the required Companies House information and login details. Having everything ready helps avoid delays during the filing process.
You will typically need:
- Your Companies House WebFiling email and password
- Your company authentication code
- Access to your confirmation statement
- Your updated SIC code selections
- Identity verification details if required
Some company officers may also need GOV.UK One Login verification depending on recent Companies House identity verification requirements. Once verified, directors receive a personal verification code linked to their identity.
Companies House has also confirmed that identity verification only needs to be completed once. After that, the verification code can be reused for future filings where required.
It is also worth reviewing your current company profile before submitting changes. Many businesses update multiple company details at the same time, including registered office addresses or director information.
If you are uncertain about which SIC code applies to your activities, reviewing competitor company filings or the official SIC code directory can help you choose the most accurate option before submission.
Preparing these details in advance makes the filing process faster and reduces the risk of mistakes on your confirmation statement.
How Do You Choose the Correct SIC Code for Your Business?
Choosing the right SIC code is important because it affects how your company is classified publicly and administratively. The best approach is to select codes that accurately reflect your primary business activities rather than choosing broad or unrelated categories.
Companies House provides an official condensed SIC code list organised into industry sections. Reviewing these carefully can help you match your services, products, or operations correctly.
You can also compare SIC codes used by businesses similar to yours on the Companies House register.
How Many SIC Codes Can a UK Company Have?
A UK limited company can use up to four SIC codes at the same time. This is useful if your business operates across multiple sectors or provides several services.
For example, a company may combine:
- Manufacturing activities
- Retail operations
- Consultancy services
- Property management
Using multiple codes gives a clearer overview of your operations while improving the accuracy of public records.
However, it is still important to focus on your main commercial activities. Adding unrelated SIC codes simply to widen your business profile can create confusion for investors, insurers, and regulators.
Industry experts often recommend reviewing your SIC codes annually alongside your confirmation statement to ensure they still reflect current operations accurately.
What SIC Codes Are Used for Dormant or Non-Trading Companies?
Dormant and non-trading companies must still provide SIC codes when filing with Companies House.
The most commonly used classifications are:
- 99999 – Dormant Company
- 74990 – Non-trading company
These codes help Companies House distinguish inactive businesses from active trading companies. Even if your business is temporarily inactive, accurate classification remains important for maintaining compliant records.
A Companies House article also explained that dormant companies still need valid SIC codes despite not actively trading. This helps preserve consistency across the public company register and ensures company statuses remain properly categorised.
Selecting the correct dormant or non-trading code also reduces confusion during compliance reviews or when third parties examine your company profile.
What Happens After You Change Your SIC Code?
After submitting your confirmation statement, Companies House reviews the filing before updating the public register. Once accepted, your new SIC code becomes visible on your company profile through the Companies House search service.
The update helps lenders, suppliers, investors, and government bodies understand your company’s current activities more accurately. In many cases, businesses notice improved consistency between their branding, services, and official records after updating their SIC code.
If you filed online, updates are usually processed more quickly than postal submissions. Companies House may contact you if additional clarification is needed, although this is uncommon when the correct procedures are followed.
Your SIC code does not directly control what your company is legally allowed to do. Instead, it acts as an administrative classification for public records and statistical purposes.
Keeping this information updated demonstrates professionalism and helps avoid outdated industry descriptions remaining attached to your business profile.
Can the Wrong SIC Code Cause Problems for Your Business?
Yes, using the wrong SIC code can create unnecessary complications for your company. Although SIC codes do not limit your legal trading activities, they still influence how your business is categorised by regulators, financial institutions, and public databases.
An inaccurate code may affect:
- Grant or funding eligibility
- Insurance assessments
- Industry-specific compliance reviews
- Investor confidence
- Public business credibility
For example, if a company still appears under a manufacturing SIC code after moving into digital services, external organisations may misunderstand the nature of the business.
Some businesses have also reported confusion during financial applications because lenders relied on outdated SIC classifications visible on Companies House records.
A business publication discussing SIC code changes noted:
“Having the wrong SIC code can not only filter you out of official searches, but it also makes your administration skills look poor.”
This highlights why reviewing SIC codes regularly is an important administrative responsibility for growing UK businesses.
Which Industries Commonly Require Specific SIC Codes?
Some industries require especially accurate SIC code selection because they operate within regulated, technical, or government-linked sectors. Choosing the wrong classification in these areas can create administrative confusion or compliance concerns.
Technical, engineering, scientific, and public administration sectors often rely on precise SIC coding for reporting and regulatory purposes.
What Are Common SIC Codes for Technical and Engineering Businesses?
Engineering and scientific companies frequently use highly specific SIC codes depending on their activities.
| SIC Code | Business Activity |
| 71122 | Engineering-related scientific and technical consulting |
| 71111 | Architectural activities |
| 71129 | Other engineering activities |
| 71200 | Technical testing and analysis |
| 72110 | Biotechnology research and development |
| 72190 | Scientific research and engineering development |
These classifications help accurately identify specialist industries and support clearer business reporting.
Companies operating across multiple technical sectors may use several SIC codes together where appropriate.
Which SIC Codes Apply to Government and Public Administration Activities?
Public administration and international organisations also use dedicated SIC classifications.
Common examples include:
- 84110 – General public administration activities
- 84210 – Foreign affairs
- 84220 – Defence activities
- 84230 – Justice and judicial activities
- 84240 – Public order and safety activities
- 84300 – Compulsory social security activities
- 99000 – Activities of extraterritorial organisations
These classifications are typically reserved for government bodies, diplomatic organisations, and public sector institutions.
Using accurate sector-specific SIC codes ensures proper classification across public records and national reporting systems.
What Are the Most Common Mistakes Businesses Make When Changing SIC Codes?
Many businesses make avoidable errors when updating SIC codes, particularly if they rush the process or choose classifications without reviewing official descriptions carefully.
Common mistakes include:
- Selecting overly broad SIC codes
- Forgetting to remove outdated activities
- Using unrelated classifications
- Choosing codes based only on keywords
- Delaying updates after major business changes
Some businesses also incorrectly assume SIC codes determine what activities they are legally allowed to carry out. In reality, SIC codes mainly serve as administrative classifications.
Another frequent issue involves companies adding too many unrelated SIC codes in an attempt to appear more diverse commercially. This can actually weaken the accuracy of company records and create confusion during funding or insurance reviews.
Reviewing competitor filings and comparing official SIC descriptions can help reduce mistakes before submission.
Businesses should also remember that changing a SIC code does not automatically update HMRC tax registrations or other regulatory records. Separate updates may still be required depending on operational changes.
How Can You Update Other Company Information Alongside SIC Codes?
When filing a confirmation statement, many companies choose to review and update additional company details at the same time. This helps keep public records fully accurate and reduces future administrative work.
Alongside SIC code updates, businesses can commonly review:
- Registered office address
- Director information
- PSC (People with Significant Control) details
- Share structure updates
- Company name changes
- Accounting reference dates
Companies House provides online filing services for most routine company updates, making the process more efficient than traditional paper filing.
If directors or shareholders recently changed, it may be practical to update those records during the same filing cycle as your SIC code amendments.
Businesses should also ensure that information held with HMRC matches their Companies House filings where necessary. Although Companies House manages company records, certain operational or tax changes may still require separate HMRC notifications.
Keeping all company details updated improves transparency and helps maintain confidence among lenders, suppliers, and customers reviewing your business profile.
Conclusion
Changing your SIC code on Companies House is an important step whenever your business activities evolve or your existing classification no longer reflects what your company does. The process is relatively straightforward and can usually be completed through a confirmation statement filed online.
Accurate SIC codes help maintain reliable public records, improve transparency, and reduce confusion for regulators, investors, insurers, and customers. They also support funding applications, compliance processes, and overall business credibility.
Whether you are correcting an original mistake, expanding into new services, or updating dormant company information, reviewing your SIC codes regularly is considered good business practice.
Most importantly, keeping your company information accurate demonstrates professionalism and helps ensure your Companies House profile reflects the true nature of your business activities in the UK.
Frequently Asked Questions About Changing SIC Codes on Companies House
Can you change your SIC code at any time?
Yes, you can change your SIC code whenever needed by filing a confirmation statement with Companies House. If the update is urgent, you can submit an early confirmation statement instead of waiting for the annual due date.
Is changing a SIC code free on Companies House?
Changing a SIC code is included as part of the confirmation statement filing process, which requires a filing fee. Online submissions are usually cheaper and processed faster than paper filings.
How long does it take for a SIC code change to appear?
Online confirmation statements are often processed within a few working days after submission. Postal applications may take longer depending on Companies House processing times.
Can a company have more than one SIC code?
Yes, a UK limited company can use up to four SIC codes to describe different business activities. This helps companies accurately represent multiple services or operational areas.
Do sole traders need SIC codes?
Sole traders are generally not required to register SIC codes with Companies House because they are not incorporated limited companies. However, SIC classifications may still appear in certain HMRC or statistical contexts.
What happens if your SIC code is incorrect?
An incorrect SIC code can create confusion for lenders, insurers, investors, and government organisations reviewing your business profile. It may also affect eligibility for grants, tenders, or sector-specific opportunities.
Can you remove old SIC codes from your company?
Yes, outdated SIC codes can be removed when filing your confirmation statement. It is recommended to remove classifications that no longer reflect your current business activities.
Do dormant companies need SIC codes?
Yes, dormant companies must still provide a valid SIC code when filing with Companies House. The most commonly used dormant company SIC code is 99999.