Hi, the tenants we have in one of our houses seems to have another person living with them.  I need to address this with them, but what do I say if they say he's "just visiting"?  What constitutes "living" there, and not "visiting".  He comes in the middle of the night.  I doubt he will pass a background check. 

What do you have in your lease? I define it by having someone there more than 7 days :)

I also say no subleasing and require every on the lease.

Yep, check your lease. If you don't spell it out in there then you might be screwed until renewed time.

What does your rental agreement say? If it is addressed in your rental agreement and they are in violation, serve them a legal "Notice to Comply" or whatever the equivalent is for your jurisdiction.  Take photos of the unauthorized occupant's car. Get up early in the morning to see who is leaving in the morning and document date, time and observation.  Let your tenants know you know someone else has been staying there.... "We understand you have an overnight guest staying with you. When did they first arrive? How long will they be staying? What is their name? Where do they live?" Refresh the tenant's memory of who is an authorized occupant and who is not.

An example of something you may want to add to your lease:

ASSIGNMENT.  Tenant agrees not to sublet said premises, nor assign this agreement, nor any part thereof without prior written consent of Landlord.

OCCUPANCY.  Tenant agrees that the premises are to be used and occupied by Tenant and members of Tenant’s immediate family only as specified in this rental agreement, namely ____________________________________.  Other persons may not move into the premises, even temporarily, without Landlord's prior written consent.  If Tenant allows a person to occupy the residence without Landlord’s consent, Tenant agrees to pay a penalty fee of fifty dollars ($50) per violation, per person.  

GUESTS.  Landlord will allow Tenant to host guests on the premises and Tenant agrees to accept responsibility to ensure guests do not violate any of the terms of the rental agreement. Tenant agrees to obtain prior written consent from Landlord for any guest staying more than fourteen (14) days in any 12 month period.  Landlord may at any time ask guests to leave the premises for violation of any of the terms of the rental agreement.  If a guest stays for more than 30 days, Landlord will require guest to either leave immediately or, upon approval of Tenant and Landlord, enter into a written agreement for further occupancy or tenancy.  If a guest refuses to leave after being asked to do so, Landlord may give legal notice to terminate the tenancy, resulting in the removal of both Tenant and guest.

I had the exact same issue,it can be an exhausting experience if it's not cited properly in the lease. There is sound advice here,good luck! They can certainly stretch the truth. I had a case of a boyfriend staying there but would get up early and come in late. I ended up having property manager stake it out!

We have month to month leases only. And we were very clear everyone over 18 has to pass background check, and I think we have something in the lease, as I remember discussing it with them when they signed the lease. The lease runs from the 1st to the last of the month. If I need to change something in the lease, do we do it on the 1st? do we tell them before?

@Dawn Young

 Is the extra body in the property causing problems?  How did you find out they moved in?  How is the tenant on the lease?  

Before I go chest poking I look at all the data.

Frank