What Is a SIC Code? A Complete UK Guide

Published: 17 September 2026 3:44 pm Author: Oliver Stanley

Every UK company on the register has at least one, most people only ever think about theirs twice: once at incorporation, when a dropdown box asks for it, and once a year later when a confirmation statement asks whether it’s still right. In between, the SIC code sits quietly in the background, doing a job most directors never had explained to them.

This guide covers what a SIC code actually is, how to find or choose one, how many a company can have, how to change one, and how it differs from an objects clause, a term that trips up a fair number of people looking into this.

What Is a SIC Code?

A SIC code, short for Standard Industrial Classification code, is a 5-digit code that describes what a business does. Every UK company is required to have at least one SIC code on file at Companies House, and can have up to four.

SIC codes aren’t a Companies House invention. They come from a wider classification system used across UK statistics, originally developed to let government bodies group and compare businesses by the type of economic activity they carry out. Companies House uses a condensed version of the full list maintained by the Office for National Statistics, and filings are checked against that condensed list, so a code that exists in the wider ONS system but isn’t on the Companies House version will get a filing rejected.

How Is a SIC Code Used in Business?

Practically, a SIC code’s main job is descriptive rather than functional. It tells Companies House, and anyone searching the public register, what kind of business a company is in, everything from “management consultancy” to “hairdressing and other beauty treatment.”

Beyond the public register, SIC codes get used more widely than most directors realise:

Government statistics on business activity, sector growth, and the wider economy are built from aggregated SIC code data.
Lenders and credit reference agencies often factor a company’s SIC code into risk models and industry benchmarking.
Due diligence and compliance checks, including anti-money laundering risk assessments, can flag certain SIC codes for closer scrutiny, since some sectors carry higher inherent risk than others.
Company formation agents, insurers, and some suppliers may ask for a SIC code as a quick way of understanding what a business does before looking any further.

None of this makes the SIC code a high-stakes filing, but it does mean an inaccurate or overly generic one can create friction later, for reasons that have nothing to do with Companies House itself.

How Many SIC Codes Can a Company Have?

A company can have between one and four SIC codes. There’s no requirement to use all four, most companies with a single, clear line of business only need one, but if a company genuinely operates across multiple distinct activities, using more than one code gives a more accurate picture than forcing everything under a single description.

LLPs are the exception here: a SIC code is not required for an LLP. This requirement applies to companies only.

How Do I Find My Company’s SIC Code?

If you already have a company and want to check what SIC code (or codes) are currently on file, the quickest way is to search for your company on the Companies House Find and Update service, which is free and public. Your company’s overview page lists its current SIC code(s) alongside its registered office, incorporation date, and filing history.

If you’re setting up a new company and need to choose a SIC code for the first time, Companies House provides a condensed SIC code list with a searchable online lookup tool, so you can find the code that best matches your intended business activity before you incorporate. Only codes on that condensed list are valid for a Companies House filing, so it’s worth using the official lookup rather than an older or unofficial list.

Examples of SIC Codes

To give a sense of what a SIC code actually looks like, here are a handful of commonly used examples:

62012 – Business and domestic software development
70229 – Management consultancy activities (other than financial management)
69201 – Accounting and auditing activities
68209 – Other letting and operating of own or leased real estate
56102 – Unlicensed restaurants and cafes
82990 – Other business support service activities not elsewhere classified

If none of the available descriptions match a company’s activity precisely, it’s normal and expected to choose the closest available option rather than leaving it blank, since a code is mandatory.

How Do I Change, Add, or Remove a SIC Code at Companies House?

There’s no standalone Companies House form for changing a SIC code. The only way to add, remove, or update one is by filing a confirmation statement.

In practice, that gives two options: wait until the company’s next scheduled confirmation statement is due and update the SIC code as part of that filing, or file an early confirmation statement if the correct SIC code needs to be reflected on the public register sooner, for example because a lender, insurer, or other third party has specifically asked to see it corrected. Filing early doesn’t cost anything extra beyond the standard confirmation statement fee, and it resets the company’s 12-month review period from that new filing date.

If you’re managing this through Kudocs, filing a confirmation statement to update a SIC code is quick to do directly from your dashboard. See our guide on filing a confirmation statement and our confirmation statement FAQs for more detail.

Are SIC Codes the Same as Objects Clauses?

No, and this is one of the more common points of confusion. SIC codes don’t have the same legal status as objects clauses. They describe what a company does, more or less accurately, but they don’t restrict what activities a company is legally allowed to carry out.

Objects clauses are a different, older concept. Companies incorporated before the Companies Act 2006 came into force (before 1 October 2009) were required to include objects clauses in their articles of association, which legally restricted the company to specific activities. Under the Companies Act 2006, the default position flipped: a company now has unrestricted objects unless its articles say otherwise. Charities and other non-profits set up for a specific purpose are still commonly required to have restrictive objects clauses, but the vast majority of modern companies operate with unrestricted objects and simply describe their activity through a SIC code instead.

The upshot: changing a SIC code changes how a company is described on the public register. It does not, on its own, change what the company is legally permitted to do.

Does an Incorrect SIC Code Cause Problems?

Not in the sense of a Companies House penalty. Choosing an approximate or slightly outdated SIC code isn’t a filing offence in the way missing a confirmation statement deadline is. But there are practical downsides worth knowing about:

Filing rejection: if a code isn’t on the current Companies House condensed list at all, the filing containing it will be rejected outright.
Lender and risk-model friction: an inaccurate or unusually broad SIC code can distort how credit reference agencies or lenders classify the business, which occasionally shows up in due diligence or lending decisions later.
Compliance flags: because certain SIC codes correlate with higher money-laundering risk in sector-based AML models, a mismatched code can prompt questions from a bank or adviser that a more accurate one wouldn’t have.

None of this is usually urgent, but if a company’s activity has genuinely changed since incorporation, correcting the SIC code at the next confirmation statement (or sooner, if needed) is a small task that avoids these knock-on frictions.

How Do SIC Codes Affect Company Registration in the UK?

A SIC code is a mandatory part of registering a UK company. Incorporation can’t be completed at Companies House without selecting at least one valid code from the condensed list, alongside the other required details like registered office and director information. It doesn’t affect whether a company can be registered in a substantive sense, there’s no rejection based on what business activity is chosen, only on whether the code itself is valid, but it is one of the fields incorporation simply won’t go through without.

FAQs About SIC Codes

Can a company have no SIC code?

No. Every UK company must have at least one valid SIC code on file, both at incorporation and on every confirmation statement afterwards. There’s no option to leave it blank.

Can I remove a SIC code from Companies House entirely?

You can remove additional SIC codes if a company has more than one and no longer needs them, but you can’t reduce a company down to zero. At least one valid code always has to remain on file, updated through a confirmation statement like any other SIC code change.

Do LLPs need a SIC code?

No. The SIC code requirement applies to companies only. LLPs are not required to provide one.

Is there a specific SIC code for a limited company?

No, “limited company” describes a legal structure, not a business activity, so there’s no single SIC code that applies to it. Every limited company chooses a SIC code (or up to four) based on what it actually does, whether that’s software development, retail, consultancy, or something else entirely.

Does my SIC code need to match exactly what my company does?

It should be the closest available match on the condensed list, but it doesn’t need to be a perfect description. Many companies operate slightly differently from any single SIC code description, and choosing the nearest reasonable fit, or combining up to four codes where genuinely relevant, is the accepted approach.

I can’t find the SIC code for what my company does?

You’re not alone, and there’s a real reason for it. Companies House works from a condensed list of UK SIC 2007, around 600 codes across 21 sections, not the full ONS classification, and that condensed list is what incorporation forms, confirmation statements, and WebFiling or API filings all check against. SIC 2007 was fine for its time, but plenty of business models in use today simply didn’t exist when it was drawn up, so coming up short on a genuinely close match isn’t unusual.

A newer classification does now exist: UK SIC 2026, published by the ONS on 31 July 2026, which replaces SIC 2007 and brings the UK back in line with the revised international NACE structure. Companies House hasn’t moved to it yet. In a May 2026 blog post, Companies House confirmed that a future SIC framework is under active discussion with the ONS, but nothing has been agreed or implemented, and any change would need legislation first.

So for now, if nothing on the list is an exact match, the official advice, and ours, is to pick the closest available option rather than leave the field blank. It’s far from ideal, but it’s the only route Companies House currently accepts. We’ll update Kudocs as soon as Companies House moves to a new SIC framework.

How Kudocs Handles SIC Codes

Since a SIC code can only be changed through a confirmation statement, keeping it accurate comes down to the same discipline as keeping any other confirmation statement detail current. In Kudocs, updating a SIC code happens as part of filing a confirmation statement directly from your company dashboard, whether that’s your next scheduled filing or an early one. See our guide on filing a confirmation statement or check our confirmation statement FAQs for the detail.

The Takeaway

A SIC code is a small, easily overlooked detail: five digits that describe what a company does, required at incorporation, checked at every confirmation statement, and changeable only through that same filing. It doesn’t restrict what a company can legally do, that’s a separate, largely historical concept in objects clauses, but it does feed into statistics, lender risk models, and compliance checks in ways that make it worth getting right rather than leaving on autopilot from the day a company was formed.

If you’re managing SIC codes and confirmation statements across more than a handful of client entities, see how Kudocs keeps company details accurate and filings on track year-round, or book a 15-minute demo to see it against your own client list.