Subletting in Germany (Untermiete): The Rules You Must Follow (2026)

Subletting is everywhere in Germany, students taking in flatmates, tenants letting their place during a long trip, the whole Zwischenmiete market, but it runs on rules many tenants ignore at their peril. The central one: you almost always need your landlord's permission, and subletting quietly without it can cost you your home. The reassuring counterpart: German law often protects your right to sublet, especially part of your flat, and stops landlords refusing without good reason. Between those two truths sits a clear path to subletting safely, and a clear warning about doing it wrong. Getting it right matters whether you are taking in a flatmate or letting your flat while away.

This guide covers subletting in Germany: when you need permission, when the landlord cannot refuse, the risks of going without consent, and how to do it properly. Sublet openly and safely, not quietly and dangerously.

You usually need permission

Start with the rule that governs everything: as a tenant, you generally need the landlord's permission to sublet all or part of your flat (Untermiete).

• Subletting all or part of the flat usually requires the landlord's consent
• Subletting without consent is a serious breach
• It can lead to termination of your lease

So the default is ask first. Whether you want to take in a flatmate, let a room, or sublet the whole flat while you are away, you should get the landlord's permission before doing it. The "sublet quietly and hope nobody notices" approach is genuinely dangerous in Germany, because unauthorised subletting is a breach that can end your tenancy.

This applies to the obvious cases (taking on a flatmate in your WG, letting your place during a trip) and to the Zwischenmiete market, which is simply structured, permitted subletting. The common thread: subletting is normal and allowed, but it must be done with the landlord's knowledge and consent, not behind their back.

So before any sublet, your first step is always the same: ask the landlord. The good news, next, is that they often cannot reasonably say no.

When the landlord cannot refuse

Here is the tenant-protective counterweight: the landlord cannot always refuse.

German law often protects the tenant's right to sublet part of the flat when there is a legitimate interest:

• For example, taking in a flatmate for financial or personal reasons (income, companionship, a partner moving in)
• In such cases, the landlord cannot unreasonably refuse

So if you have a genuine reason to sublet part of your flat, the law is frequently on your side, the landlord must have a valid reason to refuse, not just reluctance. They may refuse for legitimate grounds (such as overcrowding, or a specific unsuitable subtenant), but they cannot withhold permission arbitrarily when you have a legitimate interest in subletting a room.

The distinction matters:

• Subletting part of the flat (a room, taking in a flatmate): strong tenant protection, landlord cannot unreasonably refuse given a legitimate interest
• Subletting the whole flat (letting your entire place): the landlord has more discretion to refuse

So your right is strongest when you want to keep living there and take in someone else, and weaker when you want to hand over the whole flat. Either way, you still ask, but for partial subletting with a real reason, a refusal may itself be challengeable. If a landlord unreasonably refuses a legitimate partial sublet, a tenant association can advise on your rights.

The risk of doing it without consent

To underline why permission matters, the risk of unauthorised subletting is severe:

• It is a breach of your tenancy
• It can give the landlord grounds to warn you and, if it continues, terminate your lease
• You also remain fully responsible to the landlord regardless (next section)

So the downside of skipping permission, potentially losing your home, vastly outweighs the minor convenience of not asking. Some tenants assume a quiet sublet is harmless, but discovery (a neighbour mentions it, the landlord visits, post arrives for an unknown name) can trigger a warning or termination. Given that landlords often cannot reasonably refuse a legitimate partial sublet anyway, going without consent is doubly foolish: you take a serious risk to avoid asking for something you might well be granted.

The lesson is simple and firm: never sublet without consent. Ask, get permission (ideally in writing), and you remove the single biggest risk. The convenience of secrecy is never worth your tenancy.

You stay liable, and how to do it right

A crucial point tenants underestimate: even with a subtenant, you remain liable to the landlord.

• You stay responsible for the rent, the condition of the flat, and the deposit, even while a subtenant lives there
• If the subtenant damages the flat or does not pay you, you are still on the hook to the landlord

So subletting does not transfer your responsibilities, it adds a layer. The landlord's contract is with you; if your subtenant trashes the place or stops paying, the landlord still looks to you for the rent, the repairs, and the deposit/condition. You are effectively a mini-landlord to your subtenant while remaining a tenant to your landlord, with all the risk that implies.

This is exactly why you must choose subtenants carefully and protect yourself on paper.

How to sublet properly:

1. Ask the landlord for written permission first, explaining who the subtenant is and the terms
2. Once approved, put a written sublet agreement in place with the subtenant, covering rent, duration, and responsibilities
3. Vet the subtenant, since you remain liable for their conduct
4. Keep deposit and condition matters clear between you and the subtenant
5. Beware sublet scams, both as a subletter and a subtenant, fake sublets are common

Doing it openly and on paper protects everyone: the landlord knows and consents, you have an agreement to enforce against the subtenant, and the responsibilities are clear. A handshake sublet to a stranger, without permission or a contract, is how people lose both their deposit and their lease.

The bottom line: subletting in Germany is normal but rule-bound. You usually need the landlord's permission, and going without it risks your lease, but the law often protects your right to sublet part of your flat, so a legitimate partial sublet usually cannot be unreasonably refused. Whatever you do, you stay fully liable to the landlord for rent, condition, and deposit. So sublet the right way: written permission first, a written agreement with a vetted subtenant, and everything clear and on paper.

What to do this week

• Always ask your landlord for written permission before subletting all or part of your flat, since unauthorised subletting can cost you your lease.
• Know your rights: for a legitimate partial sublet (like taking in a flatmate), the landlord often cannot unreasonably refuse, though they have more discretion over whole-flat sublets.
• Protect yourself, you remain liable to the landlord for rent, condition, and deposit, so vet your subtenant and put a written sublet agreement in place.

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