When raising rent on a month-to-month tenant, what document do I need to use?

[Kelsey P.]

I have month-to-month tenants and I need to raise the rent. I understand how much notice I need to give them yet I did not know what document I need to use to make this change reflected in the lease since this is not a lease extension. Do I use the "Residential Lease Amendment" to note the increase in rent? Thanks