Always refer to your lease. If allowed; screen and BG check and add to lease or deny. I upcharge for adding people, and have maximums. 2 for 1 bed; 3 for 2 bed; 4 for 3 bed. Make sure you screen well.
I would follow your normal application process with the friend. As Bjorn said, make sure you screen the friend. If she doesn't meet your set rental criteria, I would not move forward with renting to her. I also think it would be a good idea to charge more monthly for adding an occupant. Make sure you are following your lease and your local/state laws as well. Good luck!
I would ask why they want to do this. How much time is left in lease? You could create a new lease, after screening new person, with additional rents. More people equals more wear and tear on property. And more risk for you.
I would simply say no. Adding a adult and child is a huge increase in wear and tear.
Chances are they will be charging them rent and I do not allow my tenants to sub let in my leases.
If you agree to their request, thoroughly screen (highly unlikely they will pass) and tell them you will be increasing the rent by 30%. May as well make a profit for your additional work load and expenses.
How many residents live there currently? 4 adults and 1 child in a three bedroom starts to get tight and will drive up certain utility expenses and increase wear and tear.
Screen, screen, screen and ask questions. Why is this roommate looking to move? Don't allow someone else's problems to become yours.
I once allowed a roommate to move her boyfriend in after confirming her roommates were on board with it and it became a nightmare.
Interesting discussion here. We have always had to follow a local rule of "U+2" here, so two families living together never really happens. Charging more for rent if someone is adding a tenant? 30% even, hmmm. Makes me think. The logic behind it is sound. What if it was a 2 Bedroom/1 Bath that was marketed to the open public and the person who took it, happened to be a single individual. Then, upon moving in, after 6 months, that person got a significant other and wanted to move them in. So, 2 people in one unit, which originally, you probably would have suspected that, being a 2/1, would have 2 people living there. Would you then charge additional rent too? If you didn't would that be a fair housing issue? Hey! Why didn't you charge him more rent, when he added a roommate and I had to pay a 30% premium because we added a 3rd person? I'll have to dive in and check to see if this is legal in our city and state.
Thanks for the questions and responses.