Moving into new premises, expanding into the unit next door, or switching what you actually do in a space you already occupy — all of these can trigger planning rules most business owners never think about until it’s too late. Get it wrong and you could be trading illegally, facing enforcement action, or stuck paying rent on a property you can’t legally use for its intended purpose. Here’s what every UK business owner needs to know before signing a lease or changing how a property is used.
The basics: what counts as a “change of use”
Every property in England has a designated “use class” under planning law — a category that defines what it can legally be used for. Shops, offices, cafés, gyms and clinics were all separate classes until 2020, when the government merged most of them into a single, broader category called Class E (“commercial, business and service”). The idea was to let high street premises flex between compatible uses without needing permission every time.
If you’re moving from one Class E use to another — say, converting a former shop into an office, or turning a beauty salon into a small gym — you generally don’t need planning permission at all, because both uses sit inside the same class. But not everything fits neatly inside Class E. Pubs, hot food takeaways, cinemas, and drinking establishments are treated as “sui generis” — literally “of their own kind” — meaning any change involving them almost always needs a full planning application, in both directions.
Worked example: A sole trader running a hairdressing salon (Class E) wants to convert it into a small café with seating (also Class E). No planning application is needed, because both uses fall within the same class — though building regulations may still apply for things like ventilation or fire safety.
Worked example: A limited company wants to convert a redundant pub into office space. Because pubs are sui generis, this is a full change of use and will need planning permission, regardless of how minor the physical works are.
When you don’t need permission — permitted development rights
Beyond Class E, there are specific “permitted development” routes that let you change use without a full application, provided you meet set conditions. The most relevant for small business owners is Class MA, which allows certain Class E premises to convert to residential use through a “prior approval” process rather than a full planning application. It’s faster and cheaper than a standard application, but it’s not automatic — the building must have been in Class E use for at least two years, and the council still assesses issues like flooding, noise and transport impact before signing it off. Prior approval isn’t guaranteed just because you qualify for the route.
When you definitely need permission
You need a full planning application whenever a change is “material” — significant enough to genuinely alter the character of how the site is used — and it isn’t covered by an existing permitted development right. Common examples for small businesses include:
- Converting a shop or office into a hot food takeaway
- Changing agricultural land or buildings into commercial use
- Converting residential property into a business use where the business dominates (regular customer visits, deliveries, employees on site)
- Any change involving a sui generis use, in either direction
- Check the property’s current lawful use class with the local planning authority before signing anything — don’t rely on what the previous occupier was doing, as unauthorised uses don’t become lawful just because nobody’s been caught.
- If you’re planning any change of use, apply for a Lawful Development Certificate if you’re not sure whether permission is needed — this gives you a formal, legally binding answer rather than a guess.
- Factor in time. Prior approval and planning applications both take weeks to months, and can affect a targeted opening date.
- Remember planning permission and building regulations are separate systems — securing one doesn’t cover the other, and most physical alterations will need building regs sign-off regardless of the planning position.
- Check any restrictive conditions attached to older planning permissions or lease covenants, which can limit what Class E otherwise allows.
Working from home sits in a genuine grey area. If you’re a sole trader doing admin and calls from a spare room, that’s unlikely to need permission — the property remains primarily a home. But if the business starts to dominate the property, with regular client visits, delivery vehicles, or staff coming and going, it can tip into a material change of use, even without any building work taking place. The same logic applies to short-term letting: the occasional Airbnb night is unlikely to trigger anything, but running a property as a full-time short-term let can be treated as a distinct sui generis use requiring permission.
Why this matters whether you’re a sole trader or a limited company
The legal duty to check and comply with planning rules sits with whoever occupies and uses the premises — it doesn’t change based on your business structure. But the practical stakes differ. A sole trader operating from home risks disrupting their own living arrangements and facing enforcement notices personally. A limited company taking on a commercial lease risks sinking fit-out costs into a property before discovering the intended use isn’t lawful — and landlords don’t always know or check this themselves, so don’t assume a signed lease means the use is compliant.
Worked example: A limited company signs a five-year lease on a unit last used as a bank, intending to run it as a fitness studio. Both uses fall under Class E, so no planning permission is needed — but the company should still check the lease itself doesn’t restrict the unit to financial services use, since planning law and lease terms are separate things entirely.