Sublease agreement: what it is and who's liable

A sublease agreement is a contract in which a tenant rents all or part of their leased space to someone else, while their own lease with the landlord stays in force. Say a nurse in Sacramento takes a three-month travel assignment and rents her apartment to a graduate student from June to August. The sublease is between the nurse and the student. The nurse's lease with the landlord does not go away. If the student stops paying, the landlord still looks to the nurse for the rent [2].

That last point is the one people miss. A sublease adds a second contract underneath the first. It does not move the original tenant's obligations to the newcomer. This guide covers United States residential and commercial subleases, using New York Real Property Law § 226-b and California's state tenant guidance as worked examples. It is general information, not legal advice. Subletting rules differ by state, by city, and by the wording of each lease.

The vocabulary is simple once you see the structure:

• Master lease (or prime lease). The original lease between the landlord and the tenant.
• Sublessor (or sublandlord). The original tenant, who now also acts as a landlord to someone else.
• Subtenant (or sublessee). The person who moves in under the sublease.

"Sublet" and "sublease" name the same arrangement. New York's Attorney General uses both words for one transaction, and calls the original tenant the "prime tenant" [1]. A sublease is not the same as an assignment, and that difference decides who the landlord can chase for money. More on that below.

If you want the wider picture of the master lease itself, start with what a lease agreement is. This article focuses on the layer underneath it.

Sublease agreement: purpose and uses

A sublease solves a timing problem. The tenant needs to leave for a while, or needs help with the rent, but the lease term has not ended. California's Department of Real Estate (DRE) describes the two classic cases. One is a tenant with more space than they need who rents out a room. The other is a tenant who leaves for a set period and plans to come back, such as a student away for the summer [2].

Common uses include:

• Temporary absence. A work posting, a semester abroad, or a long family visit.
• Shared rent. Taking in a housemate who pays the original tenant, not the landlord.
• Downsizing a business. A company that leased more office or warehouse space than it now needs rents the surplus to another firm. The commercial version follows the same structure, with a master lease, a sublessor, and a subtenant. See our guides to the commercial lease agreement and the warehouse lease agreement for the master-lease terms that usually govern it.
• Bridging a move. A tenant who must relocate before the term ends, and who does not want to break the lease.

A sublease is the right tool when the original tenant wants to keep the lease, or at least keep the option to return. If the tenant wants to leave for good, an assignment or a release from the lease may fit better. California's guidance draws exactly that line: a sublease suits a temporary move, an assignment suits a permanent one [2].

Sublease or assignment

The two are easy to confuse because both put a new person in the space. The difference is who owes the landlord.

	Sublease	Assignment
What transfers	Part of the tenant's interest, often for part of the term	The tenant's whole interest in the lease
Who the newcomer pays	The original tenant	The landlord directly
Newcomer's duty to the landlord	None directly, only to the original tenant	Directly responsible for rent and damage
Original tenant still liable	Yes	Yes, unless the landlord releases them

California's DRE explains that under a sublease, the subtenant pays the original tenant. The subtenant "has no direct responsibility to the landlord, only to you" [2]. Under an assignment, the new tenant becomes directly responsible to the landlord. Even then, the original tenant stays legally responsible unless the landlord explicitly releases them. A full release needs a written three-way agreement called a novation [2].

New York draws the same distinction. Its Attorney General describes a sublet as transferring less than the entire interest, and an assignment as transferring the entire interest and moving out permanently [1].

Sublease agreement: parties

Three parties have a stake in every sublease, even though only two sign it.

The landlord. The landlord is not a party to the sublease itself, but controls whether it may happen. Many leases prohibit subletting without the landlord's prior consent. California's DRE says a tenant may sublease unless the rental agreement precludes it without the landlord's prior consent. If it does, the tenant must get permission first [2]. The landlord's contract, and its claim to the rent, stays with the original tenant [2].

The sublessor (original tenant). This party carries two sets of obligations at once. To the landlord, they still owe everything in the master lease. To the subtenant, they now owe whatever the sublease promises. California's DRE puts it plainly: the original tenant "is still responsible for paying the rent to the landlord and functions as a landlord to the subtenant" [2]. In New York, a tenant whose sublet the landlord approves under Real Property Law § 226-b "remains liable to the landlord for the obligations of the lease, including all future rent" [1].

The subtenant. The subtenant gets the right to occupy the space on the sublease's terms. Their rights should not exceed the original tenant's. California's DRE gives two examples. A tenant on a month-to-month agreement should not promise the subtenant a fixed term. A tenant whose lease bans pets cannot allow the subtenant a pet [2].

Other people may need to sign off too. New York's sublet request process asks for the written consent of any co-tenant or guarantor on the original lease [1]. A guarantor who backs the master lease has a direct interest in who lives in the unit.

Sublease agreement: key clauses

A good sublease answers every question the subtenant and sublessor might later argue about. California's DRE lists the core items. They are the rent amount and due date, where the rent goes, and who pays each utility. They also include the start and end dates, a list of possessions left in the unit, and the conditions of care and use. The DRE also stresses that the sublease must be consistent with the master lease [2].

The clauses below carry the most weight. For the meaning of the word itself, see our glossary entry on clauses.

Parties and premises. Name the sublessor, the subtenant, and the landlord. Describe exactly what is sublet: the whole unit, one bedroom, or a defined area of an office. List included furniture, parking, and storage.

Master lease reference. State that the sublease is subject to the master lease, and attach a copy. This is how the subtenant learns the rules they must follow, such as noise, pets, alterations, and permitted use. It also gives the sublessor a contractual basis to hold the subtenant to those rules.

Landlord consent. Record whether the landlord's consent is required and whether it has been given. Attach the written consent. Where the lease requires consent but sets no standard for giving it, California's DRE says the clause is construed to mean consent will not be unreasonably withheld [2]. Do not rely on that reading anywhere else without checking local law and the lease wording.

Term. Give a fixed start date and end date. In most cases, end the sublease on or before the master lease. California's DRE warns that a subtenant should not get greater rights than the original tenant, such as a fixed term the tenant does not hold [2]. Regulated housing can differ. In New York, a rent-stabilized sublease may run past the end of the prime tenant's lease, and the prime tenant, not the subtenant, keeps the right to a renewal lease [1].

Rent and payment. Set the amount, due date, payment method, and late fee. Say whether the subtenant pays the sublessor or, by arrangement, the landlord directly. Some regulated housing caps what a subtenant can be charged. In New York, a rent-stabilized tenant may charge a subtenant no more than the stabilized rent, plus a 10% surcharge for a furnished sublet [1].

Security deposit. State the amount, who holds it, what it may cover, and when it comes back. The sublessor's own deposit with the landlord is a separate matter and stays in place.

Utilities and services. Assign each utility. California's DRE names gas, electric, water, trash, and telephone as the typical list [2]. Add internet and any shared building charges.

Use and conduct. Restrict use to what the master lease allows. Ban further subletting or assignment without consent from both the sublessor and the landlord.

Condition and inspection. Agree on a move-in checklist and photos. This is what settles deposit disputes later.

Default and termination. Say what happens if the subtenant misses rent or breaks a rule, and how much notice each side must give to end early.

Our sublease agreement template sets out these sections in order, from master lease details and consent documentation through deposit, utilities, and termination.

Dates and lifecycle events

A sublease runs inside another contract's timeline. That makes its dates more fragile than a normal lease's, because two clocks are running.

Consent request. Consent comes before move-in. In New York, Real Property Law § 226-b sets a formal process for tenants in buildings with four or more units. The tenant sends a written request by certified mail, return receipt requested. The request must give the sublease length, the subtenant's name and home and business addresses, and the reason for subletting. It must also give the tenant's address during the sublet, any co-tenant or guarantor consent, and a copy of the proposed sublease [1].

Landlord response window. Under that New York process, the landlord may ask for more information within 10 days of the request being mailed. The landlord must then send consent, or the reasons for refusal, within 30 days of the request or of its own information request, whichever is later. If the landlord sends no written notice, New York treats the silence as consent [1]. Diarise both deadlines on the day the request goes out.

What a refusal means. The New York consequences depend on the building and the reason. In New York buildings with four or more units, tenants have a right to sublet with the landlord's advance consent. If the landlord refuses on reasonable grounds, the tenant cannot sublet and is not released from the lease. If the refusal is unreasonable, the tenant may sublet anyway [1]. In New York buildings with three or fewer units, a tenant has no right to sublet. If that landlord unreasonably refuses, the tenant's only remedy is release from the lease on 30 days' notice [1].

Commencement and move-in. Start the sublease only after consent is in hand. Complete the inspection checklist on the first day.

Rent dates. Two rent dates now matter. The subtenant's payment to the sublessor should land before the sublessor's payment to the landlord is due. A gap of a few days protects the sublessor from paying late while waiting on a subtenant.

Sublease end and master lease end. Outside special regimes such as New York rent stabilization, set the sublease end date on or before the master lease end date. If the master lease renews or has a notice deadline, that deadline still belongs to the sublessor. Our guide to contract renewal explains how renewal and notice terms interact.

Duration limits. Some regimes cap how long a tenant may sublet. A New York rent-stabilized tenant may not sublet for more than two years within any four-year period [1].

Move-out and deposit return. Inspect against the move-in checklist, settle deductions in writing, and return the deposit on the agreed timeline.

Risks and common mistakes

Most sublease disputes trace back to one of a few mistakes. Each is avoidable with a written agreement and a calendar.

Subletting without required consent. This is the biggest risk. In New York, a sublet or assignment that does not comply with the law "may be grounds for eviction" [1]. In California, a tenant whose rental agreement prohibits subleases must get the landlord's permission first [2]. Elsewhere, the consequences depend on state law and the lease's default clause, so read both before anyone moves in.

Assuming the subtenant takes over the liability. They do not. In both New York and California, the original tenant stays liable to the landlord after a sublease [1] [2]. If the subtenant damages the unit or stops paying, the landlord can hold the original tenant responsible. The original tenant then has to pursue the subtenant under the sublease.

Promising more than the master lease allows. A subtenant should not be given greater rights than the original tenant holds [2]. A longer term, a pet, or a business use that the master lease forbids puts the sublessor in breach.

No written sublease. California's DRE says any sublease "should be in writing to avoid disputes" [2]. Verbal arrangements leave rent, deposit, and end dates open to argument.

Treating a short-term rental as a sublease. California's DRE warns that most rental agreements prohibit short-term rentals through sites such as Airbnb. Many local laws prohibit them too, with heavy fines [2].

Missing the master lease's own dates. A sublessor who is away can miss a renewal notice or rent increase notice under the master lease. The sublease does not pause those obligations.

Overcharging in regulated housing. In New York, an overcharged rent-stabilized subtenant may file a complaint with the state housing agency or sue the prime tenant. In court, they may recover the overcharge plus interest, attorneys' fees, and treble damages where applicable [1].

For a broader framework on spotting and ranking these exposures, see contract risk management. If you have a draft sublease in hand, a quick pass with a contract review tool can surface missing clauses before anyone signs.

Contract-management checklist

Treat a sublease as two linked contracts, not one. File the master lease, the sublease, and the landlord's consent together, so anyone who opens one finds the others. Our guide to building a contract repository covers how to structure that.

Capture at signing:

• Names and contact details for the landlord, sublessor, subtenant, and any guarantor
• The exact space sublet, and what is excluded
• Master lease start date, end date, rent, and renewal or notice terms
• Sublease start date, end date, rent, due date, and payment method
• Who holds each deposit, and the amount
• The landlord's written consent, with its date
• Utility responsibilities by service
• Early termination rights and notice periods on both contracts

Diarise:

• The landlord's response deadline on a consent request, where local law sets one
• Monthly rent dates for both payments, with a buffer between them
• The sublease end date, with a reminder 30 to 60 days ahead
• The master lease's renewal and notice deadlines
• Any statutory cap on sublet duration
• The deposit return deadline after move-out

Review on a cadence:

• Monthly: confirm the subtenant's rent arrived before the master lease rent was due
• Quarterly: check that utilities and any shared costs are settled
• Before any master lease renewal or amendment: check whether the change affects the sublease
• At the end of the sublease: run the move-out inspection and close the deposit

You do not need software to do this for one apartment. A shared folder and a calendar are enough. When a company manages several subleased offices or warehouses, the dates multiply quickly. Contracko can store the related agreements in one place and use AI to extract key dates from them. It also lets you set multiple reminders per contract that can repeat when a contract renews, and sync contract dates to Google Calendar, Apple Calendar, or Outlook [3]. Our documentation explains how contract dates and auto-renewals work. The contract management best practices guide covers the habits that keep linked agreements from drifting apart. You can try it with a free trial, and see current plans on the pricing page.

Sources

[1] New York State Office of the Attorney General, Residential Tenants' Rights Guide (sublets and assignments under Real Property Law § 226-b, the consent process and deadlines, and rent-stabilized sublet limits). ag.ny.gov/sites/default/files/tenants_rights.pdf

[2] California Department of Real Estate, California Tenants: A Guide to Residential Tenants' and Landlords' Rights and Responsibilities, 2026 edition (subleases, assignments, novation, and consent clauses). dre.ca.gov/publications/ResourceGuidebook/2026_Landlord_Tenant_Guide.pdf

[3] Contracko, Features (contract repository, AI date extraction, repeating reminders, and calendar sync). contracko.com/features

Images in this article were generated with the assistance of AI.