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Can You Change SIC Codes on a Confirmation Statement?

Ryan Patrick

• 9 min read
Can You Change SIC Codes on a Confirmation Statement?

If your UK limited company has changed its business activities, you may need to update its Standard Industrial Classification (SIC) code at Companies House. But can you make that change through your annual confirmation statement, or do you need to submit a separate form? Yes, you can generally update your company's SIC code through a confirmation statement. The confirmation statement, filed using form CS01, allows a company to confirm or update its SIC code to reflect the nature of its business. You should select codes that accurately describe the company's current activities and ensure that the information submitted to Companies House is correct.

For example, a company originally registered to provide marketing consultancy may later develop a software product. If software development becomes part of its business, it may need to add an appropriate SIC code or replace its existing code, depending on the activities it carries out. Getting the classification right matters for more than keeping a public record tidy. SIC codes help describe what a company does, and inaccurate information can create confusion for investors, lenders, customers and professional advisers reviewing the business. This guide explains how to change a SIC code through a confirmation statement, when to make the update, how to choose the correct code, and what UK founders and international business owners should consider.

What Is a SIC Code?

A Standard Industrial Classification (SIC) code is a numerical code used to classify a company's business activity. Companies House uses SIC codes to record the nature of a company's business on the public register. For UK companies, SIC codes are generally selected from the UK Standard Industrial Classification 2007 (UK SIC 2007) list. Each code corresponds to a particular type of economic activity. Examples include:

  • 62020 – Information technology consultancy activities.
  • 62012 – Business and domestic software development.
  • 70229 – Management consultancy activities other than financial management.
  • 47910 – Retail sale via mail order houses or via Internet.
  • 73110 – Advertising agencies.

The correct code depends on the company's actual activities, not simply its name, website description or future plans. A business that sells products online, for example, should not automatically choose a software development code just because it uses a custom ecommerce website. Its classification should reflect the economic activity it actually undertakes.

Why does your company's SIC code matter?

A SIC code helps Companies House categorise a company's business activities. It can also help people reviewing the public register understand the type of work the company carries out. An accurate code can be useful when:

  • Investors assess a company's business model.
  • Lenders or commercial partners review company information.
  • Customers research a potential supplier.
  • Founders update company records following a change in direction.
  • Accountants and other advisers review a company's registered details.

However, a SIC code is not a substitute for sector-specific licences, regulatory permissions or tax registrations. Choosing a code associated with a particular industry does not, by itself, authorise a company to conduct regulated activities.

How to Change Your SIC Code Through a Confirmation Statement

Companies House allows you to update your SIC code when filing your confirmation statement. The current CS01 form includes a dedicated additional-information section for changes to a company's principal business activities or SIC codes. Follow these steps to make the change correctly.

Step 1: Check your existing SIC code

Start by searching for your company on the Companies House register. Open the company's record and review the SIC code or codes currently displayed. Compare them with the activities your business actually carries out. For example, a company registered as an IT consultancy may now earn most of its revenue from developing and licensing its own software. Its existing code may no longer adequately describe its principal activity.

Step 2: Find the correct replacement code

Use the official Companies House SIC code list. Read the descriptions carefully rather than selecting a code based on a keyword alone. Several codes may sound similar but refer to different activities. The Companies House CS01 guidance specifies using the relevant condensed SIC list when updating a company's business activity. The form currently refers to SIC 2007 codes.

Although the Office for National Statistics published an updated UK SIC 2026 classification in August 2026, that does not automatically mean Companies House filing requirements have changed to the new codes. For a confirmation statement, follow the current Companies House form and its prescribed list rather than substituting a code from a different classification.

Step 3: Decide whether to add, replace or remove a code

A UK company can generally record up to four SIC codes to describe its business activities. You do not need to list every service the company provides; select codes that best represent its actual activities.

Consider the following example. A company initially provides website design services. It later develops a subscription-based software platform while continuing to design websites for clients. Depending on the nature and importance of each activity, it may be appropriate to retain the website-related code and add a software development code.

By contrast, if the company has completely stopped providing website design services, it may be more appropriate to remove that code and retain the one that reflects its current business. The aim is an accurate classification, not the longest possible list.

Step 4: File the confirmation statement using an appropriate service

You can generally file your confirmation statement online through the relevant Companies House filing service or submit the paper CS01 form. However, the simplified online confirmation statement service cannot be used to make changes to company information. If you need to change a SIC code, you will need an appropriate alternative, such as WebFiling or the paper form.

For a paper filing, complete the SIC code change section and provide the new codes, any codes being removed, and a brief description of the principal activity if you cannot determine the appropriate code. The SIC change section must be submitted with the confirmation statement, not as a standalone filing. Before submitting, review the rest of the confirmation statement. Directors must also meet the applicable identity verification requirements, and the filing must confirm the company's information accurately.

Step 5: Check the updated public record

After submitting the confirmation statement, return to the company's Companies House record to confirm that the information has been updated correctly. Keep a copy of the filing confirmation and note the new code in your internal company records. This provides a useful audit trail if a bank, investor or adviser later asks why the company's registered business activity changed.

Do You Need to Wait Until Your Annual Confirmation Statement?

No. If your company's activities change, you can update its SIC code through an early confirmation statement rather than waiting for the usual filing date. Companies House specifically recognises this option. However, there is an important practical consideration: filing early changes the confirmation statement date and starts a new review period. You should check how this affects the company's next filing deadline before submitting an early statement.

For many small companies, waiting until the next scheduled confirmation statement is sufficient if there is no immediate need to update the public record. An early filing may make sense if the existing classification is materially misleading or the company needs its registered information to reflect a significant change in business direction.

Changing a SIC code does not, by itself, replace other obligations arising from a change in business activities. If the company enters a regulated sector, for example, it must separately consider any licensing, authorisation or compliance requirements.

How Do You Choose the Right SIC Code?

Selecting the correct code can be harder than filing it. Many businesses carry out several activities, and a company's marketing description does not always align neatly with the official classification. Use this practical framework.

1. Identify what the company actually does

Focus on the work the business carries out or the products and services it supplies. A company that develops software for customers may need a different code from one that primarily advises businesses on technology strategy. Similarly, a retailer that sells goods online should not automatically select a code for software development just because it operates an ecommerce website.

2. Identify the principal activity

Ask which activity best represents the company's main business. Revenue can be a useful indicator, although it is not necessarily the only consideration. If a business earns most of its income from software development and provides occasional consulting, a software development code may be the most suitable principal classification, with a consultancy code added if it genuinely represents a separate activity.

3. Add other codes only where they are justified

If a company has multiple substantial activities, additional codes can provide a more accurate picture. For example, a business might manufacture products, sell them online and provide repair services. Depending on the precise activities, more than one code may be appropriate.

Avoid adding codes merely because the company might offer those services in the future. The classification should describe the business meaningfully, rather than serve as a wish list.

4. Check unusual or specialised activities carefully

If the company's business involves financial services, healthcare, legal services or another regulated area, distinguish between its SIC classification and any regulatory permissions it may need.

A SIC code does not establish that the company is authorised to provide a regulated service. Where the correct classification is unclear, consult the official code descriptions and seek professional advice where necessary.

What If Your Company Has the Wrong SIC Code?

If you discover that your company has an incorrect SIC code, you can generally correct it through the appropriate confirmation statement filing. The first step is to establish whether the code was wrong from the beginning or whether the company's activities have changed since incorporation. For example:

  • A company registered as a management consultancy may have always operated primarily as a software developer.
  • A company originally formed to provide graphic design services may have moved into ecommerce.
  • A dormant company may have started trading and now need a code that reflects its business activity.

In each case, choose the code that best represents the relevant business activity and update the Companies House record through the prescribed process. An inaccurate SIC code does not automatically make a company's incorporation invalid. Nevertheless, leaving incorrect information uncorrected can create confusion during commercial reviews and may make the company appear less carefully managed.

If the issue is part of a wider change in the business, review other company information as well. Changes to directors, people with significant control, registered office details and other particulars may require separate notifications rather than being dealt with solely through the confirmation statement.

Does Changing a SIC Code Affect Tax or Companies House Fees?

Changing a SIC code through a confirmation statement does not, by itself, change a company's tax status or tax obligations. The code describes the company's business activity; it does not determine whether the company is liable for Corporation Tax, VAT or another tax. Those obligations depend on the relevant facts and applicable rules.

However, a change in business activity may coincide with changes that do affect tax. For example, a company that begins selling goods internationally may need to review VAT, customs and reporting requirements. The trigger is the underlying business activity and its circumstances, not simply the SIC code entered at Companies House. There is also a filing fee to consider. As of October 2026, Companies House charges £50 for an online confirmation statement and £110 for a paper filing. The fee is for the confirmation statement, not a separate charge for changing the SIC code.

Companies generally need to file at least one confirmation statement every 12 months, even if no company details have changed. Filing an early statement can affect the confirmation date, so consider the timing before making the change.

Frequently Asked Questions

1. Can I change my SIC code without changing my company's name?

Yes. A SIC code describes the company's business activity and can be updated without changing its registered name. You should still ensure that the code accurately reflects what the company does.

2. How many SIC codes can a UK limited company have?

A company can generally record up to four SIC codes to describe its business activities. Choose codes that reflect genuine activities rather than adding every possible service the company may provide.

3. Can I change my SIC code online?

Yes, but you need to use a filing method that supports changes. The simplified online confirmation statement service does not allow company information changes, so you may need to use Companies House WebFiling or submit the paper CS01 form.

4. Can I change my SIC code before my next confirmation statement is due?

Yes. You can file an early confirmation statement to update your SIC code rather than waiting for the scheduled date. Remember that filing early changes the confirmation statement date and starts a new review period.

5. Do dormant companies need a SIC code?

Yes. Companies House expects companies to have an appropriate SIC code even if they are dormant or not trading. The code should reflect the company's relevant status or activity as applicable.

6. Does changing my SIC code change my Corporation Tax rate?

No, not by itself. Corporation Tax treatment depends on the company's taxable profits and the relevant tax rules, rather than simply the SIC code recorded at Companies House.

7. Can I use a SIC code from the new UK SIC 2026 classification?

For a Companies House confirmation statement, follow the codes specified by the current Companies House filing form and official list. The ONS published UK SIC 2026 in August 2026, but that does not automatically replace the SIC 2007 codes specified in the current CS01 change section.

8. What happens if I choose the wrong SIC code?

An incorrect code can make the company's public record misleading. Check the official descriptions and correct the information through the appropriate confirmation statement filing. If the issue reflects a more significant change in the business, check whether any other company or regulatory notifications are required.

Conclusion

You can change your company's SIC code through a UK confirmation statement, and you do not generally need to wait until the next annual filing date if an earlier update is appropriate. The important steps are to check the company's existing classification, select codes that accurately describe its activities, use a filing service that permits changes, and verify the updated Companies House record.

For founders and international business owners, keeping the SIC code accurate is a small but worthwhile part of maintaining reliable company records. It helps ensure that the public register reflects the business you actually operate, while leaving tax, licensing and other compliance obligations to be assessed separately where necessary.