Home / Questions / What Is a SIC Code?
Last updated 23 October 2026. Written by the Limited Company Accountant UK team, part of Accotax. Figures are for the 2026/27 tax year; always check GOV.UK for the latest rates.
Short answer: A SIC code (Standard Industrial Classification) is a five-digit code that tells Companies House what your company does. You choose up to four codes when you register and can change them later.
At a glance
| Digits | 5 |
|---|---|
| Maximum codes | 4 |
| Changed via | Confirmation statement |
Choosing the right one
Pick the code that best describes your main activity, not just the closest match. Banks and some clients check it.
Changing a code
You can update SIC codes when you file your confirmation statement.
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The bottom line
A SIC code (Standard Industrial Classification) is a five-digit code that tells Companies House what your company does. If you would rather not do it alone, our fixed fees start at £45.83 + VAT a month.
Frequently asked questions
Does my SIC code affect tax?
No, but it can affect how banks and insurers view your business.
Can I use the wrong code?
Choose the most accurate one you can, since it is public information.
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Our packages start at £45.83 + VAT and cover accounts, tax and deadlines. Get a free quote or call 0203 4411 258.
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