Occasionally, I'll be asked by a landlord what they should do in situations where they don't have a signed lease agreement and the tenant isn't paying. The Arizona Residential Landlord and Tenant Act address this exact issue.
Section 33-1314(B) of the Arizona Residential Landlord and Tenant Act states: "In the
absence of a rental agreement, the tenant shall pay as rent the fair
rental value for the use and occupancy of the dwelling unit."
This rule extends to all people and not just formal tenants. So, for instance, if you invite a friend into your house to rent a room for $300 a month. Even without a written lease agreement you can evict that friend for non-payment of rent.
The "fair rental value" of an Arizona rental property can be disputed by reasonable
people it is best to make sure that you have a written lease agreement
in place before ever letting a tenant move into the property.