The answer is not yes, no, or panic
A good tenant texts on a Tuesday:
My brother is moving to town. Is it okay if he stays with me for a while and maybe gets added to the lease?
This is the kind of request that sounds harmless until it is not. Sometimes it is a responsible adult trying to do things correctly. Sometimes it is an unofficial sublet. Sometimes it is already happening and the "request" is really a confession.
For a small landlord, the goal is simple: do not accidentally approve a new resident without screening, paperwork, and a clear rent/lease decision.
Use three possible answers:
- Yes, after approval and paperwork
- Not yet, send an application first
- No, the lease and occupancy rules do not allow it
Avoid the fourth answer, which is silence followed by months of pretending you do not know another adult lives there.
First, decide whether this is a guest or an occupant
Most leases allow normal guests. Tenants can have dinner guests, weekend visitors, out-of-town family, and friends who stay over occasionally. A lease that bans all visitors is not realistic and may be hard to enforce.
An occupant is different. That person lives there.
Ask practical questions:
- How many nights per week will they sleep at the property?
- Are they receiving mail there?
- Are they moving furniture, clothes, pets, or vehicles there?
- Will they have keys or access codes?
- Are they contributing to rent or utilities?
- Are they leaving another primary residence?
- How long is "temporary" supposed to last?
Your lease may already define this. For example, it might say a guest becomes an unauthorized occupant after staying more than a certain number of days in a month. If your lease has that language, use it. If it does not, update your next lease version.
Do not get cute with labels. If someone is sleeping there five nights a week, keeping belongings there, and using the address, calling them a "guest" does not make the risk disappear.
Check occupancy limits before you screen
Before asking for an application fee or running background checks, make sure the unit can legally and practically support another person.
Look at:
- Local occupancy standards
- Bedroom count and legal bedroom definitions
- Septic capacity, if relevant
- Parking limits
- HOA or condo rules
- Fire safety and egress
- Lease limits on residents
Many landlords have heard "two people per bedroom" as a rule of thumb, but occupancy law is more nuanced. Fair housing rules also matter, especially when children are involved. Do not create a blanket rule that effectively discriminates against families. If you are near the limit or unsure, check your local requirements before deciding.
If the property is a small house with plenty of legal occupancy capacity, the answer may be straightforward. If it is a one-bedroom unit with two adults, two children, one unofficial partner, three cars, and an HOA parking policy, the answer deserves more care.
Require the same application process you use for any adult applicant
If the new person will live at the property, they should apply like any other adult resident.
That usually means:
- Rental application
- Government ID verification
- Income or employment verification, if they will be financially responsible
- Credit report, where permitted
- Background check, where permitted
- Eviction history review
- Landlord references
- Pet or assistance-animal information, if applicable
Use the same written screening criteria you use for new vacancies. This is not the moment to improvise because the current tenant is nice or because the new person is someone's cousin.
Consistency matters for two reasons.
First, it protects the property. A person who moves in mid-lease can cause damage, create neighbor issues, bring unauthorized animals, or refuse to leave later. You want to know who they are before they get keys.
Second, consistency protects you. If you screen one proposed roommate strictly but wave through another, you may have a fair housing problem even if you did not intend one.
Decide whether the new person is an occupant or a tenant
These are not always the same thing.
An authorized occupant has permission to live there but may not be financially responsible for rent. This is common for minors, dependents, or sometimes an adult family member in specific situations.
A tenant is a party to the lease. They are usually jointly responsible for rent, damages, lease violations, notices, and move-out obligations.
For most unrelated adult roommates, adding the person as a tenant is cleaner. If rent is unpaid, damage occurs, or the original tenant leaves, you do not want an adult resident saying, "I live here, but I never agreed to any of that."
That said, do not rely on generic internet forms for this decision if local law treats occupants, tenants, subtenants, or lodgers differently. A short attorney-reviewed lease addendum is often worth it.
Do not create a partial approval by text
Texting "sure, that's fine" can create more trouble than you meant.
Instead, reply with process:
Thanks for asking before making changes. Any adult who will live at the property needs to apply and be approved before moving in. If approved, we will sign a lease addendum before they receive keys or use the property as their residence. Until then, the current lease guest limits still apply.
That message is not hostile. It is a boundary.
If the tenant says the person has already moved in, do not ignore it. Respond in writing:
The lease does not allow additional occupants without written approval. Please have them submit an application by Friday, and do not issue keys or parking access unless approval is complete. If they are not applying, they need to stop occupying the property and remain within the lease guest limits.
Adjust the wording to your lease and state law. The important part is that you document the issue before it becomes your new normal.
Review rent, deposit, and utilities
Adding another adult may change the economics of the tenancy.
Questions to decide:
- Does rent change when an additional resident is approved?
- Are utilities separately metered, tenant-paid, or included in rent?
- Does water, sewer, trash, or HOA cost increase with another occupant?
- Does the security deposit need to increase, and is that legal in your state?
- Are there new pets or vehicles?
- Does renters insurance need to list the new tenant?
Be careful with mid-lease rent increases. If the lease fixes rent for the term, you may not be able to raise it simply because the tenant asked to add a roommate unless your lease allows that or everyone signs an amendment. At renewal, you have more flexibility, subject to local rules.
Security deposit rules also vary. Some states cap deposits based on rent or require specific handling and notices. If you collect an added deposit, document exactly what it is for and update the ledger.
Put the approval in a lease addendum
If approved, write it down.
The addendum should cover:
- Full legal name of the added person
- Whether they are a tenant or authorized occupant
- Effective date
- Whether all existing lease terms apply
- Rent amount, if changed
- Security deposit change, if any
- Utilities and shared charges
- Parking, keys, mailbox, storage, pets, and amenity access
- Confirmation that no other occupants are approved
- Signatures from the landlord and all existing adult tenants
Have all current tenants sign, not just the new person. If two roommates are already on the lease and one wants to add a partner, the other roommate needs to know who is being added and what obligations change.
Also decide whether this is an addendum to the current lease or a brand-new lease. If the current lease ends in two months, it may be cleaner to approve the person as an occupant for the remainder and handle full tenant status at renewal. If ten months remain, a proper lease amendment matters more.
If you deny the request, give a clean reason
A denial should be boring and tied to written criteria.
Examples:
- The applicant does not meet published screening criteria
- Occupancy limits would be exceeded
- HOA or building rules do not allow the proposed arrangement
- The current lease prohibits subleasing or additional occupants
- The tenant refused to complete the approval process
Avoid personal explanations like "I do not like the situation" or "I have a bad feeling." Those may be true, but they are not the reason you want in the file.
If you deny based on a consumer report, follow adverse action notice requirements. If fair housing issues may be involved, especially disability accommodation or family status, slow down and get local guidance.
Watch for the soft unauthorized move-in
Not every tenant asks first.
Signs of an unauthorized occupant include:
- A new car parked overnight most days
- Neighbors reporting a new resident
- Maintenance vendors seeing another bedroom set up
- Mail or packages for someone not on the lease
- The tenant casually mentioning "we" after months of living alone
- A guest who never seems to leave
Do not start with accusations. Start with documentation and a neutral request:
We have noticed indications that an additional person may be occupying the property. The lease requires written approval before any new occupant moves in. Please confirm who is currently residing at the property by May 10. If someone needs to be added, we can provide the application process.
If they refuse, follow your lease enforcement process. That may mean a cure notice, non-renewal, or other local procedure. The details are state-specific, so do not wing it if the tenant pushes back.
Fix your lease before the next request
If this situation feels messy, your lease may be too vague.
For the next lease cycle, make sure your documents address:
- Names of all approved tenants and occupants
- Guest limits
- Definition of unauthorized occupant
- Application requirement for new adult residents
- No subleasing or assignment without written consent
- Parking and vehicle registration
- Utility responsibility
- Pet and assistance-animal process
- Tenant responsibility for guest conduct
- What happens if someone moves in without approval
You do not need a lease that reads like a military manual. You do need enough clarity that a reasonable tenant understands the process before their cousin's mattress is in the living room.
The small-landlord rule
When a tenant wants to add a roommate mid-lease, treat it like a mini leasing event.
Confirm whether the person is a guest or occupant. Check occupancy limits. Screen consistently. Decide whether they become a tenant. Put the result in writing. Then update rent, deposits, keys, parking, and records before they move in.
The tenant may see it as a household change. You should see it as a risk change. Handle it calmly and early, and it stays routine.
You might also like:
- How to screen rental applicants: what to collect, what to evaluate, and how to stay legal
- Non-residents are using your rental property amenities: what small landlords should do
- Pest control in a rental lease: what small landlords should spell out
If you want one place to keep applications, lease addenda, tenant notes, and property records together, ManorKeeper is built for self-managing landlords. See how it works.