When Mandatory Licensing Applies

Mandatory licensing is the one HMO scheme that applies everywhere in England, without a council having to opt in. If your home crossed its threshold and your landlord had no licence, they were committing an offence — wherever in the country you lived.

The threshold

Since 1 October 2018, a licence is required for any HMO occupied by:

five or more people, forming two or more households, who share a toilet, bathroom or kitchen.

That is the whole test. There is no discretion in it and no local variation — every council in England must operate it.

The storey rule is gone

Before October 2018 mandatory licensing only caught HMOs of three or more storeys. That requirement was abolished. A five-person house over two floors, a large ground-floor flat, a converted bungalow — all are now caught if they meet the test.

This is worth dwelling on if you rented before and after that date, because a property that was lawfully unlicensed in 2018 may have become an offence on 1 October that year without anything about it changing.

Counting correctly

Two numbers matter, and people routinely get both wrong.

People, not bedrooms

Count everyone living there as their only or main residence. That includes:

• children, including babies;
• a couple sharing one room — that is two people;
• a lodger, or a partner who moved in later;
• anyone occupying informally, even without a written agreement.

Households, not tenancies

A household is people who are related or living together as a couple. Everyone else is separate. So a couple plus three unrelated friends is five people and four households — over the threshold on both counts, even though the tenancy might name only one person.

What is not caught

• A single family, however large — one household.
• Four or fewer occupiers — though these are frequently caught by a council’s additional licensing scheme instead.
• Genuinely self-contained flats, each with its own kitchen and bathroom behind its own lockable door — though the building itself may be a section 257 HMO.
• Buildings owned or managed by public bodies, and certain student halls managed under an approved code of practice.
• Properties where the resident landlord lives with no more than two lodgers.

The offence, and the defences

Controlling or managing an unlicensed HMO that requires a mandatory licence is an offence under section 72(1) of the Housing Act 2004. It is a strict liability offence: the landlord does not have to have intended anything.

Two defences exist, and both are narrow:

• Section 72(4) — an application for a licence had been duly made, or a temporary exemption notice had been given. The word “duly” is decisive: incomplete applications, and applications made after the tenants moved in, have repeatedly failed at tribunal.
• Section 72(5) — the landlord had a reasonable excuse. The burden is on them, and simply not knowing about the scheme is not enough.

What it is worth

Because mandatory licensing applies nationally, these are usually the most straightforward RRO claims to establish: either the property met the threshold or it did not, and either there was a licence or there was not.

For offences committed on or after 1 May 2026 the maximum award is 2 years’ rent, and you have 2 years from the offence to apply. For earlier offences the limits are 12 months and 12 months.

How to check

1. Count the people and the households for the period you lived there.
2. If it was five and two or more, a licence was required — anywhere in England.
3. Search your council’s public HMO register for the address.
4. Compare the licence dates and the holder’s name against your own tenancy dates.

If the register shows no licence, an expired one, a gap, or a different holder for part of your tenancy, that is worth investigating.

This article is general information about the law in England and is not legal advice about your own circumstances. Exemptions are more detailed than the summary above. The rules differ in Wales, Scotland and Northern Ireland.