It is not unusual to list an investment property for sale while it is occupied, and while there needs to be both an understanding and an ideally a written agreement with the renters - does the current lease include a section on this possibility? - this can be accomplished if you did not plan for this possibility.
You really need a written agreement, its in your best interest.
The most daunting part of the process may be getting potential buyers in the property - renters can be difficult. Working with them on a peaceful agreement is paramount. Additionally you want for the property to show well - renters may not be willing to keep the dishes out of the sink or the bath clean - and this can pose a very serious problem when the property is seen. It turns buyers off.
1. Get an agreement in writing with your tenants - offer an incentive!
2. Bring your realtor into the mix and make sure everyone is clear about the showing instructions, process, obligations and NOTICE. This is key.
Coldwell Banker Preferred, Philadelphia