Increasing rent. Owner occupied duplex

[Jon Weaver]

Hey BP,

My wife and I recently bought our first investment property as a owner occupied duplex. We moved into one side and the tenants on the other sides lease is up Dec 31 2021. The current rent is about $400/mo lower than market rents. We sent them a new lease for 2022 for a little lower than current market rents. They replied and said they would go month to month after their current lease ends. My question is what can be done to increase the rent? Can I tell them that month to month will be the same rate as signing a new lease or will they legally only have to pay $1200/mo?