A rent increase form letter should include the date of the notice, the name and address of tenant, the new rent amount, and the effective date of the increase, states About.com. Local and state laws govern rental agreements, so the legal requirements for the notice vary by locality.
In addition to listing the terms of the new rental agreement, landlords should sign the notice. They should also include a place for the tenant to sign and accept the new terms or decline them in writing, suggests About.com. Landlords who lease rental properties should ask tenants to sign a new lease reflecting the change. Oral notice of a rent increase is not legal in most states, and some states require a certified letter to notify the tenant of any changes, explains Nolo.
In most states, landlords must give at least 30 days notice of the new terms, but state law may require the landlord to offer the tenant more time, notes Nolo. California law requires that landlords give month-to-month tenants 60 days notice if they increase the rent by more than 10 percent within 12 months, according to the California Department of Consumer Affairs. State and local statutes may also govern how much a landlord can raise the rent within a certain time period, explains Landlordology.