What is a SIC Code? Meaning | Examples & How to Choose One

A SIC code, short for Standard Industrial Classification code, is a five-digit number that describes what your business does. In the UK, Companies House and HMRC use it to categorise businesses by the type of trade or activity they carry out. If you have ever registered a limited company or filed a confirmation statement, you have already come across one. Choosing the right SIC code might seem like a small admin task, but it can have a real impact on how your business is viewed by HMRC, banks, and insurers.

What is a SIC Code and What Does It Actually Mean?

A SIC code is a classification number used by Companies House to identify the nature of your business activities. Every company registered in the UK must provide at least one SIC code when it is formed and update it each year as part of the confirmation statement.

The full name is Standard Industrial Classification, and the system has been in use in the UK since 2007, when it was updated to align with EU standards. The version used today is known as SIC 2007.

Each code is five digits long. For example:

• 62012 – Business and domestic software development
• 69201 – Accounting and auditing activities
• 47710 – Retail sale of clothing in specialised stores

Companies House groups these codes into sections, divisions, groups, and classes, ranging from broad industries right down to specific activities.

Have questions about your limited company? Our limited company accountants in London are happy to help.

Who Needs a SIC Code?

If you have a limited company registered at Companies House, you need at least one SIC code. You can have up to four codes if your business operates across different areas.

Sole traders are not required to register a SIC code with Companies House, but HMRC may use similar classification data when processing your Self Assessment tax return, particularly if you claim certain expenses or fall into a specific trade category.

How Do I Find the Right SIC Code for My Business?

Companies House provides a full list of SIC codes on its website. You can also use their SIC code search tool when setting up a company or filing a confirmation statement.

The best approach is to search for words that describe what your business actually does, not just the industry you are in. For example, if you run a cleaning company, you would not just search for “cleaning”, you would think about whether you clean domestic properties, offices, or industrial sites, as each of these has a different code.

How to Choose Your SIC Code Step by Step

Step 1: Write down exactly what your business does
Be specific. Do you sell products or provide services? Do you work with the public or other businesses? Do you manufacture anything?

Step 2: Use the Companies House SIC code tool
Go to HMRC’s Portal and use the search function during company formation or when filing your confirmation statement.

Step 3: Look at the description carefully
Each SIC code comes with a short description. Read it thoroughly before selecting it. Some codes look similar but apply to very different businesses.

Step 4: Pick up to four codes if needed
If your business does more than one thing, you can use up to four SIC codes. Always list the one that represents your main business activity first.

Step 5: Review it each year
Your business can change over time. Check your SIC code when you file your confirmation statement and update it if your activities have shifted.

Does It Matter If the SIC Code Is Wrong?

Yes, it can matter more than most people realise.

A wrong SIC code might not immediately land you in trouble, but it can create problems down the line in several ways.

Can the Wrong SIC Code Trigger a Tax Investigation?

It can increase your chances of being looked at more closely by HMRC. If your SIC code suggests your business operates in a particular industry, but your expenses, turnover, or profit margins do not match what is typical for that industry, it can raise a flag.

For example, if your SIC code says you run a restaurant, but your business accounts show no food supplier costs, that inconsistency could invite scrutiny.

Will It Affect My Business Bank Account?

Potentially, yes. Banks use your SIC code when you apply for a business account. Some banks automatically decline applications from companies in certain categories — often without explaining why. If your SIC code does not accurately describe your business, you might find yourself refused a bank account or flagged for enhanced due diligence.

Does It Affect My Business Insurance?

Yes. Your insurer may use your SIC code as part of their risk assessment. If the code does not match your actual activities and you ever need to make a claim, the insurer could argue that the policy does not cover you properly.

Have questions about your limited company? Our limited company accountants in London are happy to help.

Is There a Penalty for the Wrong SIC Code?

Companies House does not currently issue fines specifically for an incorrect SIC code. However, if it is part of a wider pattern of inaccurate filings, it could contribute to a more serious compliance issue. It is always better to get it right.

Which SIC Codes Are High Risk?

Some SIC codes attract more attention than others, from banks, insurers, HMRC, and even Companies House itself. These tend to be sectors that are commonly used for fraud, money laundering, or other financial crime.

What Makes a SIC Code High Risk?

A SIC code becomes high risk when businesses in that category are statistically more likely to be involved in financial irregularities, or when the nature of the work makes it harder to verify income and expenses.

Common High-Risk SIC Codes in the UK

Here are some categories that are frequently flagged as higher risk:

Money services and currency exchange

• 64992 – Activities of financial services, not elsewhere classified
• 66190 – Other activities auxiliary to financial services

Businesses that deal in cash, currency conversion, or crypto assets often find it difficult to open bank accounts using these codes.

Construction and labour supply

• 43999 – Other specialised construction activities not elsewhere classified
• 78200 – Temporary employment agency activities

These sectors are commonly associated with payroll fraud, VAT fraud, and CIS (Construction Industry Scheme) abuse.

Import and export

• 46900 – Non-specialised wholesale trade

Businesses using this code may face additional scrutiny because it is broad and can be used to disguise the nature of goods being traded.

Recruitment and staffing. Staffing agencies, particularly those supplying workers to the construction, hospitality, or care sectors, are often subject to closer HMRC review due to the risk of umbrella company abuse and off-payroll working issues.

Online retail and marketplace selling E-commerce businesses sometimes attract attention when declared income does not match visible trading activity.

If your business does genuinely fall into one of these categories, that is absolutely fine — just make sure your records are clean, your accounts are accurate, and you are working with a qualified accountant who understands your sector.

What Are Common SIC Code Mistakes?

Getting the wrong code is easier than it sounds. Here are the mistakes that business owners make most often.

Mistake 1: Choosing the Nearest Match Instead of the Right One

The SIC code list is long and sometimes confusing. Many people pick the first result that sounds close enough, rather than searching more carefully for the one that truly fits.

For example, someone who provides IT consultancy might accidentally pick a code related to IT hardware retail. These describe very different businesses, and the mismatch could cause problems.

Mistake 2: Never Updating It

Your SIC code is not set in stone. If you start out selling physical products and later switch to providing services, your original code may no longer apply. Many business owners forget to update their code when their activities change — and this creates an inaccurate public record.

Mistake 3: Using a Vague or Catch-All Code

Codes like “Other business activities not elsewhere classified” exist for businesses that genuinely do not fit anywhere else. But some people use them simply because they are unsure which specific code to pick. This is not ideal — a vague code makes your business harder to understand for banks, insurers, and HMRC.

Mistake 4: Using Multiple Codes Incorrectly

You can use up to four SIC codes, but all four should reflect real business activities. Some people add extra codes speculatively — thinking it might help with funding or grants. This is not how the system works, and it can raise questions about what your business actually does.

Mistake 5: Confusing Limited Company and Sole Trader Requirements

Sole traders do not file with Companies House, so they do not register a SIC code in the same way. But when completing a Self Assessment return, HMRC does ask about your trade. Some sole traders mistakenly think the Companies House list does not apply to them at all, and they either skip the question or describe their trade too broadly.

What Should I Do If I Have the Wrong SIC Code?

Do not panic. Correcting a SIC code is straightforward.

You can update it the next time you file your confirmation statement with Companies House. This is filed at least once a year, so you will not have to wait long.

If you want to change it sooner, you can file your confirmation statement early — there is no fee for doing this.

Here is how to update it:

1. Log in to your Companies House WebFiling account or use the HMRC-linked service
2. Start a new confirmation statement
3. When you reach the SIC code section, remove the incorrect code and search for the correct one
4. Complete and submit the statement

If you are unsure which code to use, even after researching, speak to your accountant. We deal with this regularly and can point you in the right direction quickly.

Can I Have More Than One SIC Code?

Yes. Companies House allows you to register up to four SIC codes for your limited company. This is useful if your business genuinely operates across different areas.

For example, a business owner might run a photography studio (90030 – Artistic creation) while also selling photography equipment online (47789 – Other retail sale of new goods in specialised stores not elsewhere classified). In that case, using both codes is entirely appropriate.

The key rule is that every code you list should reflect something your business actually does. Listing codes for activities you do not carry out, even if you plan to in future, is not recommended.

How to Find a SIC Code: Useful Resources

Here are the official places to look when you need to find or check a SIC code:

• Companies House SIC Code List – Available as a downloadable PDF on the Companies House website
• Companies House WebFiling – Includes a search tool when you are completing a confirmation statement
• Office for National Statistics (ONS) – The ONS publishes the full SIC 2007 structure with detailed descriptions
• Your accountant – If you are in any doubt, a qualified accountant can advise you based on your specific business activities

The Bottom Line

A SIC code is one of those admin details that many business owners rush through without thinking twice. But choosing the right one, and keeping it up to date, is a small step that can save you from bigger headaches later.

Whether it is an HMRC compliance check, a bank account application, or a business insurance claim, having a code that accurately describes your business works in your favour.

If you are not sure whether your current SIC code is correct, or if you are setting up a new limited company and want to get it right from the start, get in touch with our team. We help small business owners and limited company directors stay on top of exactly this kind of detail, so you can focus on running your business.

Disclaimer: All the information provided in this article is general in nature; it does not intend to disregard any of the professional advice.