Adding someone to your lease after moving in is usually possible, but it takes more than a handshake. You need your landlord’s written approval, the new person has to be screened, and the change has to be documented through either a lease addendum or a replacement lease that everyone signs. Handing over a key without going through those steps can put your own tenancy at risk.
Read Your Lease Before You Ask
Start with the document you already signed. Three clauses matter.
The occupancy clause sets the maximum number of people allowed in the unit and often limits residency to the named signers and their minor children. HUD generally treats two people per bedroom as a reasonable occupancy standard, but state and local rules, unit size, and building age can shift that analysis.1Department of Housing and Urban Development. HUD Occupancy Standards Memorandum
The guest policy tells you how long a visitor can stay before the landlord treats them as an unauthorized occupant. A common threshold is 10 to 14 consecutive days. If the person you want to add has been staying over regularly, your landlord may already consider them an occupant, so it’s better to formalize things sooner rather than later.
The sublet or assignment clause matters because adding a co-tenant is not the same as subletting. When you sublet, you remain solely responsible and rent to someone else yourself. When you add a co-tenant, that person signs a direct agreement with the landlord and shares responsibility for rent and the condition of the unit.
Co-Tenant or Authorized Occupant?
Not everyone who lives in a rental has to be on the lease. Landlords sometimes allow an “authorized occupant” instead of a full co-tenant, and the distinction changes what the new person can and can’t do.
A tenant signs the lease and is bound by everything in it: paying rent, maintaining the unit, giving proper notice before moving out, covering damages. An authorized occupant has the landlord’s permission to live there but doesn’t sign, which means they owe the landlord nothing directly and have no standing to request repairs or negotiate terms. The landlord’s recourse for unpaid rent or damage runs entirely through whoever signed.
If the person moving in will split rent and share responsibility, you want them added as a co-tenant. If they’re a dependent or someone who won’t be financially responsible, authorized occupant status may be enough. Either way, the landlord needs to approve.
How to Ask Your Landlord
Put the request in writing. Email or letter is fine. Include the full name of the person you want to add, their relationship to you, and the date you’d like them to move in. A written request creates a record you can point to later.
Your landlord can say no, but only for legitimate, nondiscriminatory reasons. Common grounds include poor credit, insufficient income, a problematic rental history, or the unit being too small under the applicable occupancy standard. What your landlord cannot do is deny the request based on race, color, religion, sex, national origin, familial status, or disability. Those are the seven protected classes under the federal Fair Housing Act.2Office of the Law Revision Counsel. 42 USC 3604 – Discrimination in the Sale or Rental of Housing
If the reason given feels pretextual and you suspect the real basis is a protected characteristic, you can file a complaint with HUD or your local fair housing agency. The FHA also requires landlords to make reasonable accommodations for tenants or occupants with disabilities, including allowing assistance animals despite a no-pets policy, without a pet fee or deposit.2Office of the Law Revision Counsel. 42 USC 3604 – Discrimination in the Sale or Rental of Housing
The Screening
Once your landlord agrees to consider the addition, the new person goes through the same kind of screening you did. Expect a rental application with employment and rental history, a government-issued photo ID, proof of income such as recent pay stubs or an offer letter, and written consent to credit and background checks.
If the landlord denies the application based on information in a consumer report, federal law requires them to give the applicant an adverse action notice identifying the reporting company, explaining that the reporting company didn’t make the decision, and informing the applicant of the right to dispute inaccuracies and get a free copy of the report within 60 days.3Federal Trade Commission. Using Consumer Reports: What Landlords Need to Know
What It May Cost
Adding someone to your lease isn’t always free. The charges that commonly come up:
- An application fee to cover credit and background checks on the new applicant. Some states cap these; in most markets, expect $25 to $75.
- A rent increase, since the new agreement effectively creates a new tenancy. In rent-controlled areas, local rules may limit the size of the bump.
- A security deposit adjustment. Whether the landlord can request more, and how much, depends on your state’s deposit laws, which typically cap the total at one to three months’ rent.
None of these are guaranteed. Some landlords charge only the application fee. Knowing what’s possible keeps you from being blindsided.
Making It Official
A verbal yes from your landlord isn’t enough. The change has to be documented one of two ways.
Lease Addendum
An addendum is a separate document attached to your existing lease. It names the new tenant, states the effective date, and confirms that the new person agrees to all the terms of the original lease. Everyone signs: you, the new tenant, and the landlord. A missing signature can make the addendum unenforceable. Look for a precedence clause that says which document controls if the addendum and the original lease ever conflict.
New Lease
Your landlord may prefer that everyone sign an entirely new lease, especially if other terms are changing, like the rent or the end date. The new lease replaces the old one completely. Read every provision before signing, even if your landlord says it’s the same as before. Small changes have a way of appearing in new documents.
Joint and Several Liability
Whichever route you take, the agreement will almost certainly include a joint and several liability clause. This is the single most important thing to understand before adding anyone. Every person who signs is individually responsible for the full rent and any damage to the unit. If your new co-tenant stops paying, the landlord doesn’t have to chase them. The landlord can come to you for the entire amount, and collecting from the non-paying roommate becomes your problem. That liability runs for the whole lease term, regardless of any private arrangement you two have about splitting costs.
Don’t Just Move Someone In
Moving someone in without landlord approval is typically a material breach of your lease. Landlords take it seriously because an unscreened resident exposes them to liability.
The usual first step from the landlord’s side is a written notice to cure or notice to comply, giving you a set number of days to either remove the person or run them through the formal process. The exact window depends on your state’s landlord-tenant law, but three to ten days is common for curable violations.
Miss that window and the landlord can begin eviction proceedings. An eviction on your record makes future rentals much harder to secure, since nearly every landlord screens for prior evictions. On top of that, you’re personally on the hook for any damage the unauthorized occupant causes and any unpaid rent that follows, because they have no contractual relationship with the landlord.
The formal process takes a few weeks at most. Skipping it to save time can cost you the apartment.