What’s the difference between a co-tenant, sub-tenant, and boarder in NSW?
The label matters enormously: whether you are a co-tenant, a sub-tenant, or a boarder determines whether the Residential Tenancies Act 2010 (the Act) protects you at all.
In a sharehouse, four people might share a roof under four completely different legal arrangements — and none of them might realise it. Getting the label right tells you whether you can go to NCAT (the NSW Civil and Administrative Tribunal), whether your bond has statutory protection, and what notice you’re owed if you’re asked to leave.
The three categories at a glance
| Category | Relationship | On a lease? | RTA protects you? |
|---|---|---|---|
| Co-tenant | Direct tenant of the landlord | Yes — named on the residential tenancy agreement | Yes |
| Sub-tenant | Tenant of another tenant (the “head-tenant”) | Yes — a separate written agreement with the head-tenant | Yes — against the head-tenant |
| Boarder or lodger | Occupant under an agreement to board or lodge | No formal lease required | No |
Co-tenants
Under section 3 of the Act, a co-tenant is a tenant who is one of two or more tenants under a residential tenancy agreement. In plain terms: all co-tenants are named on the same lease and each of them holds equal rights directly against the landlord.
How you become a co-tenant
You become a co-tenant by being named in the original residential tenancy agreement. You can also be added later — but only if the landlord gives written consent to the transfer or sub-letting under section 74 of the Act. The landlord must not charge for giving that consent beyond reasonable expenses (s74(2)).
Full RTA protections apply
Co-tenants have the complete set of rights the Act provides. That includes the right to go to NCAT, entitlement to bond protection, rights to repairs under section 63, and the notice regime for termination.
Joint liability — the catch
Co-tenants are jointly and severally liable. That means the landlord can pursue any one co-tenant for the full rent debt, regardless of what the others contribute. Beyond rent, section 54 makes a tenant vicariously responsible for acts or omissions by any person lawfully on the premises — including a co-tenant who damages the property.
When an AVO changes things
If a final apprehended violence order (AVO) is made that prohibits a co-tenant from accessing the premises, that co-tenant’s tenancy is terminated by operation of section 79(1). Crucially, this does not affect the tenancy of any co-tenant not subject to the order (s79(1)).
Sub-tenants
A sub-tenant rents from an existing tenant — called the head-tenant — rather than directly from the landlord. The Act’s definition of “tenant” at section 3 explicitly includes a sub-tenant of a tenant, and the standard form agreement (Schedule 1 of the Residential Tenancies Regulation 2019) defines “landlord” to include a tenant who has granted the right to occupy to a sub-tenant.
In other words: for legal purposes, the head-tenant is the landlord in the sub-tenancy relationship.
Consent is required
A head-tenant cannot sub-let without the landlord’s written consent. Section 74(1) is clear: a tenant may sub-let the premises only if the landlord gives written consent. For a partial sub-let — for example, sub-letting one room while remaining in the property — the landlord must not unreasonably withhold consent (s75(2)). For a full sub-let of the entire property, the landlord may withhold consent even without giving a reason (s75(1)).
If a landlord unreasonably refuses a partial sub-let, NCAT can order that the sub-letting proceed (s75(5)).
What protections does a sub-tenant have?
Sub-tenants have RTA protections — but those protections run against the head-tenant, not the original landlord. The head-tenant must comply with the Act in dealing with the sub-tenant. This includes the repair obligation under section 63, the bond framework, and the termination notice requirements.
The head-tenant remains fully liable to the original landlord for rent and compliance with the head-lease. A sub-tenant’s arrangement with the head-tenant does not reduce that liability.
For more on how the bond framework works for tenants and sub-tenants, see our guide to getting your rental bond back in NSW.
Sub-letting without consent
Sub-letting without the landlord’s consent is a breach of section 74 — a term implied into every residential tenancy agreement. This can expose the head-tenant to termination proceedings. The sub-tenant’s own position may also be precarious if the head-tenancy itself is terminated. The rights and risks of obtaining sub-let permission are covered separately.
Boarders and lodgers
Section 8(1)(c) of the Act excludes boarders and lodgers entirely. An agreement under which a person boards or lodges with another person is not a residential tenancy agreement for the purposes of the Act. The note to section 10 confirms this: boarders and lodgers are not covered by this Act.
This is a hard exclusion. There is no partial coverage, no minimum-protection floor, and no access to NCAT’s tenancy jurisdiction.
What governs the relationship instead?
A boarding or lodging arrangement is governed by the common law of contract. Whatever terms were agreed — written or oral — are enforceable as a contract. But there is no statutory minimum for notice periods, bond refunds, entry conditions, or repairs.
How to tell the difference — practical tests
The legal label in your agreement is not decisive on its own. Courts and tribunals look at the substance of the arrangement. These questions help:
Do you have exclusive possession of a defined space? If you can lock your room and the owner cannot enter without your permission, that points toward a tenancy or sub-tenancy, not boarding.
Does the arrangement include services? Meals, linen changes, or cleaning provided as part of the deal point toward a boarding arrangement.
Is there a written agreement describing you as a tenant or sub-tenant? This is strong — but not conclusive — evidence of a tenancy.
Does the owner retain a key and move freely through your space? Regular access by the owner without your consent suggests boarding or lodging, not a tenancy.
Is the arrangement for a defined room or for access to the whole property? A defined, lockable room with your name attached suggests exclusive possession. A share of common facilities with no defined exclusive space suggests boarding.
Note: calling yourself a “tenant” in a document does not automatically make you one if the substance of the arrangement is boarding. Under section 11 of the Act, you can apply to NCAT’s tenancy division for a declaration on whether your agreement is a residential tenancy agreement. This is often the first step if you believe you have been misclassified as a boarder.
Why it matters — the practical differences
Bond protection
Rental bonds paid under a residential tenancy agreement must be lodged with the Rental Bond Board under the Act’s bond framework. A bond paid to a boarder’s host is not covered by this framework — there is no statutory requirement for it to be lodged, and recovering it depends entirely on the contractual terms agreed.
Termination notice
Tenants and sub-tenants are entitled to statutory notice periods before their tenancy can be terminated. Boarders are entitled only to whatever the contract says — which may be nothing beyond reasonable notice at common law.
NCAT access
Tenants and sub-tenants can apply to NCAT to resolve disputes about repairs, bond claims, rent increases, and termination. Boarders cannot use NCAT’s tenancy jurisdiction. A boarding dispute is a contract claim — it may go to NCAT’s Consumer and Commercial Division or the Local Court, depending on the nature and value of the claim.
Repairs
Under section 63, the landlord (including a head-tenant acting as landlord to a sub-tenant) must provide and maintain the premises in a reasonable state of repair. A boarder’s host has no equivalent statutory obligation — only whatever was agreed in the boarding contract.
If you need to break your tenancy before it ends, the process is different depending on whether you are a co-tenant or sub-tenant — see our guide to breaking your lease early in NSW.
If you’re a boarder — what protections do you have?
The Act does not apply to you, but you are not entirely without recourse.
Your boarding contract — even if it was verbal — is a legally binding contract. If your host takes your bond and refuses to return it without justification, you can pursue that as a contractual debt. The appropriate forum is usually the Local Court for smaller amounts, or NCAT’s Consumer and Commercial Division depending on the nature of the claim.
A separate NSW Act — the Boarding Houses Act 2012 — provides a lighter set of minimum protections if you live in a “registrable boarding house”. In broad terms, that means premises with beds for five or more residents (not counting the proprietor, manager or their relatives). If it applies, you have a right to a written occupancy agreement, occupancy principles covering repair, cleanliness, and notice of fee increases, a cap on any security deposit of two weeks’ occupancy fee, and the ability to take disputes to NCAT’s Consumer and Commercial Division. This regime is separate from — and much thinner than — the tenancy protections in the Residential Tenancies Act, but it is worth knowing about if you live in a larger boarding-house-style premises rather than an ordinary sharehouse.
General anti-discrimination law also still applies. You cannot be evicted or denied accommodation on discriminatory grounds, regardless of whether the Act covers your arrangement.
Consumer protection law may apply to the terms of a boarding arrangement, particularly if the host is running a commercial operation. The detail of those protections is outside the scope of the Act, but they are a separate avenue worth knowing about.
Not sure whether you’re a tenant, sub-tenant, or boarder?
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The label you carry in a sharehouse is not just a word — it is the difference between statutory protection and none. If you are uncertain which category applies to your situation, getting that question answered before something goes wrong is far easier than resolving a dispute afterwards.