Raising rent on tenants in place after acquisition

[Connor Farrelly]

So I am currently working on a deal that has two tenants in place who only pay $500 a month (no lease just verbal agreement). These rents are far lower than the average in the area ($750+). What actions do I have to take to put in place this new rent as well as get them on to a written lease if they choose to stay at this price increase?