Subletting, assignment and changing the names on a share

Subletting means letting all or part of your home to someone else while you remain the tenant. Assignment means handing the whole tenancy to someone else and walking away. Changing the names on a share means one joint tenant leaving and, usually, another arriving. All three need the landlord's written consent, because section 16 of the Residential Tenancies Act makes it a tenant's obligation not to assign or sublet without it.

The landlord may refuse, and a refusal matters in one useful way. If you are inside a fixed term and the landlord refuses consent to assign or sublet, section 186 lets you serve notice and leave early. Beyond that, the rules are about who the landlord's tenant is, who owes the rent, and what rights a person who is not on the lease has.

This guide covers the Republic of Ireland only. The letter builder has a written request you can adapt for each of the three situations.

Consent: when you need it and how to ask

You need the landlord's consent, in writing, before anyone who is not already a tenant moves in to pay rent to you, and before you hand the tenancy to anyone else. A short-term guest, a partner staying over, or a friend sleeping on the sofa for a few weeks is not a sublet. Someone paying you for a room on a continuing basis is.

Ask in writing, name the person, say whether it is a sublet or an assignment, and ask for a reply by a date. Keep the request and the reply. If the landlord agrees, ask for the consent in writing too; a conversation is not evidence later. If the landlord says nothing, write again and note the silence. The Act does not require the landlord to give a reason, and the RTB does not review whether a refusal was reasonable, except in the house-share situation covered below.

A lease clause that forbids subletting or assignment outright is common and lawful. It does not stop you asking, and it does not stop section 186 working if the answer is no.

Subletting without consent

Subletting without consent is a breach of your obligations under section 16. The landlord's route is a written warning giving you a reasonable time to put it right, then a 28-day notice of termination if you do not. Letting the whole home on a short-term platform while you live elsewhere is the clearest case, and the one the RTB sees most. A notice on this ground can be referred to the RTB within 28 days of service, the shorter breach window.

The person you sublet to without consent is in a weak position too. Their agreement is with you, not the landlord, and when your tenancy ends theirs ends with it. If you sublet a room while you still live there, the person is your licensee, with no rights under the Act against you or the landlord beyond the contract.

Where you sublet with consent, the Act treats your subtenant as a tenant of yours. You are their landlord for repairs, the deposit and rent reviews, and the tenancy you create with them should be registered. If the head landlord later serves a notice on you, section 70 requires you to serve a copy on the subtenant within the time the Act sets, so that they are not caught by surprise.

Assignment and the way out of a fixed term

Assignment moves the whole tenancy to a new person. From the day of the assignment the new person is the landlord's tenant, pays the rent and holds the obligations, and you have none. The landlord's consent is needed, and the landlord may want references from the new person as they would from any new tenant. The deposit is usually paid over by the incoming tenant to the outgoing one, with the landlord holding the same sum for the tenancy.

An assignment is a new tenancy for the person who takes it over. Their six-month clock, their Part 4 rights and the regime they fall under run from the day of the assignment, not from the day you moved in. If you assign a tenancy that began in 2024 to someone on 1 December 2026, their tenancy is a 2026 tenancy. Part 4 tenancies and the six-month rule explains what that means.

Section 186 is the part of this that matters most for someone who needs to leave. A tenant under a fixed-term lease who asks the landlord in writing for consent to assign or sublet, and is refused, may serve a notice of termination despite the fixed term. The notice period is the ordinary tenant period for your length of tenancy. It is 28 days under six months, 35 days up to a year, 42 days up to two years and 56 days up to four. After that it is 84 days up to eight years and 112 days beyond. The refusal does not need to be unreasonable. A landlord who does not reply has not consented; write once more, then treat the silence as a refusal and take advice from Threshold on 1800 454 454 before serving the notice. Fixed-term versus periodic tenancies covers the other routes out of a term.

When one housemate leaves

Most shares are joint tenancies: everyone named on the lease is a tenant, and each is liable for the whole rent, not only their share. If one person stops paying, the landlord may look to the others for the full amount. That is the single most important fact about a share, and it is worth saying out loud before anyone signs.

When one joint tenant leaves, the tenancy continues for the rest. The start date, the Part 4 rights and the length of tenancy for notice purposes do not change. The leaving person should tell the landlord in writing that they are going, give the date, and ask to be released from the tenancy from then. Without that, the landlord may treat them as still liable. The people staying should confirm in writing that they continue.

Replacing the leaver with a new person is in substance an assignment of one share, and it needs the landlord's consent. Ask in writing with the new person's name, and ask the landlord to confirm in writing that the new person is a tenant from the move-in date. Ask too for the RTB registration to be updated. A landlord who agrees and takes the new person's rent has in practice consented, but the written confirmation is what you want.

The deposit is the usual sticking point. The landlord holds one deposit for the tenancy, capped at one month's rent, and is not obliged to return a share to a departing housemate while the tenancy continues. The usual arrangement is that the incoming person pays the outgoing person their share directly. Agree it in writing between yourselves and note it to the landlord. The deposit comes back from the landlord only when the tenancy ends, less lawful deductions; getting your deposit back covers that.

A sharer who is not on the lease

If you moved into a share and your name was never added to the lease, you are a licensee of the tenants. The landlord's tenant is whoever signed. You have whatever rights your arrangement with the housemates gives you, and few under the Act. If the tenants leave or the tenancy ends, your right to stay ends with it.

The Act gives you one route in. Under Chapter 5 of Part 4, a person who has lived in a dwelling as the licensee of a Part 4 tenant may ask the landlord in writing to be allowed to become a tenant. The landlord must have known they were living there. The landlord may not unreasonably refuse. Make the request in writing once you have been there six months, keep a copy, and if the landlord refuses without a good reason you may refer it to the RTB. Once accepted, you are a joint tenant with the same rights and the same liability as the others.

A person who rents a room from a tenant who lives there is in the same position: a licensee of the tenant. The arrangement is outside the RTB, and the rules are those of the contract and reasonable notice. Licensees and lodgers explains what that leaves you.

Where this leaves you

Subletting and assignment both need the landlord's written consent, and the landlord may refuse. Subletting without it is a breach that can lead to a 28-day notice after a warning. A refusal inside a fixed term is also your way out of it under section 186, with the ordinary tenant notice period. When a housemate leaves, the joint tenancy continues for the rest, the deposit is settled between you, and the landlord's written confirmation of any new name is what protects everyone. A sharer not on the lease can ask to be made a tenant after six months. Put each request in writing with the letter builder, and ring Threshold on 1800 454 454 before serving any notice.