What a sublet agreement actually is

Subletting has a reputation problem. Done badly, without consent, it is how people lose their homes. Done properly, it is one of the most useful tools renting has: it is how a room stays paid for during six months abroad, and how someone else gets a home without a year of commitment.

The words, precisely

Subletting is when a tenant grants someone else the right to occupy some or all of the property they rent. The original tenant becomes an intermediate landlord, the newcomer is the subtenant, and the original agreement with the head landlord stays alive underneath it all.

It is different from being a lodger, where you live in your landlord's own home and share space with them. And it is different from assignment, where a tenant hands their whole tenancy to someone else and steps out of the picture entirely.

One useful wrinkle for flatshares: if you stay living in the property and rent a spare room to someone who shares your living space, that person is usually your lodger rather than a formal subtenant, which is a much lighter arrangement. Full subletting, where you move out and someone takes the place over, is the heavier one and the one that needs the most care.

Consent first, everything else second

Read your tenancy agreement. Almost every private tenancy either bans subletting outright or requires the landlord's consent. Subletting without consent is a ground for eviction, and in social housing it can be a criminal offence.

So ask, in writing, and get the yes in writing. Explain who, how long, and why. Many landlords say yes to a defined, dated sublet with a named person, because the alternative is a void or a leaver. A message thread is fine. A clause added to your agreement is better.

If you own your place, your own permissions matter instead: leasehold flats often restrict subletting, mortgages usually require consent to let, and your insurance needs to know. For short lets of entire homes in London, planning rules cap it at 90 nights a year.

You become the landlord, with the duties to match

The part people miss: once you sublet, your subtenant's landlord is you. If the arrangement is a tenancy, the legal duties that protect renters now point at you. Take a deposit and it must be protected in a scheme within 30 days. The rent rules, notice rules and repair obligations run through you, even though the head landlord owns the building.

You also stay fully liable upwards. If your subtenant stops paying, you still owe the head landlord every penny of rent. Price that risk honestly before you hand over keys.

What to put in writing

Names and contact details of both sides. The address and, if it is one room, which room. The dates: start, end, and what happens after the end date. The rent, when it is paid, and exactly which bills are included. The deposit: amount, where it is protected, and what it covers. An inventory with photos, signed by both of you. Notice terms for ending early. House rules that matter, such as guests, smoking and pets. Whether the head landlord has consented, attached as proof.

None of this needs a solicitor for a straightforward six month sublet. It needs an hour, a template, and the discipline to write down the boring parts while everyone is still friendly.

How this works on ZoomyRoom

Sublets are a normal part of the listings you will see on ZoomyRoom, including fixed-period ones like a six month sublet while someone works abroad. The person listing should have their landlord's consent, and you are entitled to ask to see it before you commit. A legitimate sublister will not be offended by the question. The wrong reaction to that question is itself your answer.