Assignment of the tenancy agreement: differences from changing flatmate

Changing flatmate is not the same as assigning the tenancy agreement

In a rented property, there is a difference between changing who lives with you and a tenancy agreement being assigned. That distinction matters because, legally, they do not have the same effect.

The Urban Leases Act is clear on the decisive point: the agreement cannot be assigned by the tenant without the landlord’s written consent. Article 8.1 states literally: “**The agreement may not be assigned by the tenant without the landlord’s written consent. In the event of assignment, the assignee shall take the assignor’s position vis-à-vis the landlord**” art. 8 LAU, BOE.

Simply put: if the agreement changes hands, written authorisation from the owner is required. If only the internal living arrangement between occupants changes, there is not necessarily an assignment. Confusing the two situations often creates avoidable disputes.

What assignment of the agreement is and what it really involves

Assignment of the agreement means that one person leaves their contractual position and another takes it over vis-à-vis the landlord. We are not talking about a visit, a temporary stay or a simple more or less stable cohabitation, but about a change in contractual title.

That has very important practical consequences:

1. The new occupant becomes a contractual party vis-à-vis the landlord.

2. The person assigning the agreement ceases, in principle, to be the one liable in that relationship under the agreed terms.

3. The landlord must have given their consent in writing.

If you intend for another person to “take over the flat” or assume your contractual position, it is not enough to say so verbally. Nor is it enough for the owner to know about the change and not object immediately. The legal rule requires written consent.

**Common mistake:** thinking that, because the new occupant pays their share of the rent or has lived in the property for some time, a valid change of title has already taken place. That is not the case.

Changing flatmate: cohabitation, not title

When one person leaves the property and another moves in, several different situations may arise. The most common is that the agreement remains in the name of a single person or several co-tenants, while the person sharing the home changes.

That may be perfectly possible without an assignment, but it is important not to mix the two levels:

- **Changing flatmate**: affects cohabitation and the internal organisation of the property.

- **Assignment of the agreement**: affects who appears as the tenant vis-à-vis the owner.

Cohabitation alone is not the same as title. You may live with another person, share expenses or even reorganise the use of the rooms, and yet the original agreement remains exactly the same.

**Practical tip:** if the agreement is in your name and you are going to share the property with someone else, check what the agreement states before assuming the new housemate has the same rights as you vis-à-vis the landlord.

Steps to take if the person living in the flat changes

If the change only affects cohabitation and not the contractual party, it is sensible to put the situation in writing even if there is no assignment. If what you want is for the other person to become the contractual tenant, you must ask for express authorisation.

1. **Read the original agreement** and check who appears as the tenant.

2. **Distinguish the objective**: do you only want to change flatmate or transfer the agreement?

3. **If you want an assignment**, request the landlord’s written consent before making the change.

4. **If only cohabitation changes**, keep an internal written note of who occupies the property and from when.

5. **Clarify payments and responsibilities** between cohabitants to avoid internal disputes over rent, utilities and deposit.

6. **Keep messages and documents**: they may help prove what was actually agreed if a dispute arises.

In practice, many disputes arise because the arrangement has not been properly named: the tenant thinks they are “changing flatmate”, while the owner understands that an attempt is being made to replace the tenant without permission.

What to check before speaking to the landlord

Before proposing any change, it is advisable to review three basic points:

1. **Who signed the agreement**: a single tenant, several co-tenants or a special situation.

2. **Whether there is a clause on occupants or assignments**: although it cannot override the LAU to the detriment of the tenant, it may help interpret the arrangement.

3. **Whether the change is intended to alter liability vis-à-vis the owner or not**: this is the key question.

If the new occupant is only going to live there, the owner does not automatically become part of that reorganisation. If, however, you intend for the new person to assume the contractual position, then you are dealing with an assignment and written consent is required.

**Useful action:** if you need to review your agreement or assess how to raise the issue, you can request guidance at /contacto or review support options at /valoracion-vivienda-madrid if the matter is linked to a decision about renting, selling or leaving the property.

What usually goes wrong if both concepts are not kept separate

The most common mistakes are very specific:

- Thinking that a new flatmate automatically “enters” the agreement.

- Believing that sharing the rent creates co-tenancy.

- Assuming that the landlord’s silence is the same as written authorisation.

- Allowing a de facto living arrangement to become, without more, an alleged assignment.

- Failing to document who is responsible for each obligation when occupants leave or join.

The best prevention is not to assume that living together means being the tenant. The LAU clearly distinguishes between contractual position and mere occupation of the property.

In summary

Assignment of the tenancy agreement is not the same as changing flatmate. The former changes the contractual title and requires the landlord’s written consent. The latter may be limited to a change in cohabitation without any change of contractual party.

If you want to avoid problems, the practical rule is this: **do not equate occupation with title**. If there is a replacement of the tenant, document the consent. If only who lives in the property changes, make it clear that the agreement remains the same and put the internal living arrangement in writing.

If you need in-person assistance, UBICASA is at Calle Montesa 29, Madrid, Monday to Friday from 10:00 to 15:00 and from 16:00 to 19:00.