What Is a SIC Code? How to Find and Change Yours

When you register a company in the UK, Companies House asks you to choose a SIC code. It stands for Standard Industrial Classification. It's a five-digit number that describes what your company does.

Most people pick one during registration and never think about it again. But choosing the wrong SIC code — or not updating it when your business changes — can cause problems with banks, insurers, and HMRC.

What are SIC codes used for?

SIC codes are used by:

• Companies House — to classify your business on the public register
• HMRC — to understand your business activity for tax purposes
• Banks — when you apply for a business account, they check your SIC code against your application
• Insurers — to assess risk and set premiums
• Government statistics — to track which industries are growing or shrinking

Your SIC code is publicly visible. Anyone who looks up your company on Companies House can see it.

How many SIC codes can a company have?

You can have up to four SIC codes. Most companies only need one or two. You should list codes for each distinct business activity your company carries out.

For example, a company that develops software and also runs training courses might use:

• 62012 — Business and domestic software development
• 85590 — Other education not elsewhere classified

How to find the right SIC code

Companies House uses the SIC 2007 classification. There are over 700 codes grouped into sections:

| Section | Industry | |---------|----------| | A | Agriculture, forestry and fishing | | C | Manufacturing | | F | Construction | | G | Wholesale and retail trade | | J | Information and communication | | K | Financial and insurance activities | | L | Real estate activities | | M | Professional, scientific and technical | | N | Administrative and support services | | S | Other service activities |

The easiest approach: search the Companies House SIC code list for keywords that match your business. If you provide consulting services, look under section M. If you run a restaurant, look under section I (accommodation and food).

Don't overthink it. Pick the code that most closely matches your primary business activity.

Common SIC codes

Here are the most frequently used SIC codes in the UK:

| Code | Description | |------|-------------| | 62020 | Information technology consultancy activities | | 62012 | Business and domestic software development | | 70229 | Management consultancy activities (other than financial management) | | 69201 | Accounting and auditing activities | | 82990 | Other business support service activities | | 47910 | Retail sale via mail order houses or via internet | | 74909 | Other professional, scientific and technical activities | | 68209 | Other letting and operating of own or leased real estate |

If you're a freelance developer or consultant, 62020 or 70229 are the most common choices.

How to change your SIC code

You can change your SIC code when you file your confirmation statement. You cannot change it at any other time through WebFiling.

During the confirmation statement process:

1. Review the SIC codes section — Companies House will show your current codes
2. Remove any that no longer apply and add new ones
3. Submit as part of the confirmation statement filing

The change takes effect when the confirmation statement is processed, usually within 24-48 hours.

If you need to change your SIC code urgently (before your next confirmation statement), you can file a paper form, but this is slow and rarely necessary.

What happens if I pick the wrong SIC code?

There's no penalty for having the wrong SIC code. But it can cause practical problems:

• Bank account applications — banks compare your SIC code against your described business. A mismatch can delay or block your application
• Insurance — some SIC codes carry higher risk ratings, which affects premiums
• HMRC enquiries — if your SIC code doesn't match your tax returns, it may trigger questions
• Grant applications — some government grants target specific SIC codes

It's worth getting it right, but don't panic if yours is slightly off. Update it at your next confirmation statement.

Do dormant companies need a SIC code?

Yes. Even dormant companies need at least one SIC code. If your company is dormant (not trading), you can use:

• 99999 — Dormant company, no significant accounting transactions

This is a placeholder code. When you start trading, update it to reflect your actual business activity.

Key takeaways

• A SIC code is a five-digit number that tells Companies House what your company does
• You can have up to four SIC codes per company
• Change your SIC code during your confirmation statement filing
• Pick the code that most closely matches your primary activity — don't overthink it
• Banks, insurers, and HMRC all look at your SIC code, so it's worth getting right