When you want a friend to move in to your rental unit, it's a good idea to check with your landlord first. For one thing, your lease or rental agreement might require landlord approval to bring in a new roommate (even if the new person is simply replacing a cotenant who is moving out). And if it's a matter of adding a new roommate to your current group, be sure to check whether your lease or rental agreement limits the number of occupants. If you violate a lease clause that restricts the number of occupants or requires landlord approval of new roommates, your tenancy could be at stake if your landlord finds out and is unhappy with what you did.
Even if your landlord is not in the area and never stops by (or is not likely to care if a new roommate moves in), it's a good idea to ask for the landlord's consent. The landlord will probably figure out what's going on before long, and the landlord might resent your sneakiness more than the unauthorized resident.
It's a good idea to put your request for a roommate in writing. You can customize the sample letter below to send to your landlord. Importantly, the letter highlights the potential roommate's ability to pay rent (mentioning his employment), vouches for him personally (noting how long the current tenant has known him), and offers to provide the landlord further helpful information (such as his credit report and references). Also, by offering to personally pick up a rental application, the tenant makes the process of bringing on the tenant a bit easier on the landlord.
For details on roommates, including legal limits on occupants, see Every Tenant's Legal Guide or (if you're renting in California), California Tenants' Rights.
Sample Letter to Landlord
Requesting Permission to Add a Roommate
1500 Redwood Street #4
Chicago, Illinois 00000
June 27, 20xx
10 Ocean Street
Chicago, Illinois 00000
Dear Garcia Realty,
I live at the above address, and regularly pay rent to your office.
I would like to add my friend Robert Mason to my lease, as a cotenant. Robert and I have worked together for over seven years in the IT department at Taylor & Company. Robert's supervisor, Jim Barton, will be happy to answer any questions you might have, and Robert will be glad to provide a recent copy of his credit report. You can also contact Robert's current and former landlords for references.
I would like to drop by your rental office this week and pick up a rental application for Robert.
Thank you for your consideration of this request.