When registering a company in the UK, you’ll be asked to provide something called a SIC code (Standard Industrial Classification code). At first glance it may look like a string of numbers, but it determines how your business is officially classified and how others understand what you do.
In this guide, we’ll explain what a SIC code is, why it matters, how to choose the right one, and common mistakes to avoid.
What is a SIC Code?
A SIC code is a five-digit number that identifies your company’s main economic activity. For example:
- 69203 — Tax consultancy
- 56101 — Licensed restaurants
- 41201 — Construction of commercial buildings
These codes appear on your incorporation paperwork, annual filings, and public records. They allow regulators, policymakers, and investors to compare data across industries, making business information more consistent and transparent.
Why Does Your SIC Code Matter?
Your chosen code has a bigger impact than you might expect:
- Public record: It forms part of your Companies House profile, which anyone can search.
- Compliance and eligibility: Some grants, tax reliefs, or regulations apply only to certain industries. An inaccurate code could make your company look ineligible.
- Perception: Investors, partners, and clients often check SIC codes to understand a business at a glance. The right code helps you present a clear, professional identity.
How to Choose the Right SIC Code
1. Browse the official list
SIC codes range from broad industry categories to detailed business activities. Review the official Companies House list to identify the closest match to your operations.
2. Prioritise your core activity
Select the code that best represents your main source of income or the primary focus of your business.
3. Use multiple codes if needed
You can list up to four SIC codes. Make sure your primary activity is listed first, followed by any secondary ones that reflect additional services or products.
4. Review and update
Your SIC code can change as your business evolves. If your business pivots, update your code the next time you file your confirmation statement.
Common SIC Code Mistakes to Avoid
- Failing to update: If your business changes direction, your code should too.
- Being too general: Don’t settle for a broad category if a more precise code exists.
- Listing every idea: Only add secondary codes for genuine activities, not future plans.
- Copying competitors: Their code may not apply to your main business activity. Always match the code to what you do.
Can the Wrong SIC Code Hold You Back?
Yes — while it doesn’t affect your day-to-day operations, an incorrect SIC code can cause problems over time:
- Finance and insurance: The wrong code can increase perceived risk, leading to higher premiums or reduced access to finance.
- Missed opportunities: Some tenders, frameworks, grants or tax reliefs are filtered by industry — an inaccurate code may exclude you.
- Perception and credibility: Investors, partners, and clients may check your SIC code at Companies House. A mismatch can cause confusion and undermine confidence.
Final Thoughts
Your SIC code may seem like a minor administrative detail, but it’s actually an important marker of your company’s identity. Choosing the right one helps ensure compliance, avoids unnecessary complications, and presents your business accurately to anyone who searches for your company.
Take the time to review the official list carefully before registering — a small effort now can prevent bigger issues in the future.