The most important source of information about a residential tenant’s rights and a landlord’s responsibilities is the written lease agreement. Some landlords prefer oral agreements, but it is more common for them to require the tenant's signature on a written lease—and a written lease protects the tenant more than an oral agreement. Be sure to read the lease carefully before you sign it.

A residential landlord’s ability to charge late fees generally depends on the specific language in the written lease agreement; the state’s landlord-tenant laws that may limit the amount of late fees the landlord can charge and the circumstances in which they can be charged; and the state's contract law.

Contract law in most states recognizes an implied duty of good faith and fair dealing between parties to a contract, and a residential landlord who charges late fees because the tenant is an hour late paying the rent may be in breach of the landlord’s implied duty of good faith and fair dealing—unless, for example, the lease agreement specifies an hour (12:00 p.m.) of the day by which rent is due and states that time is of the essence.

In Alaska, the residential tenant's rights and the landlord's responsibilities are indeed primarily outlined in the written lease agreement. A written lease provides a clear record of the terms agreed upon by both parties and is generally more protective of a tenant's rights than an oral agreement. Tenants are encouraged to read and understand the lease before signing. Regarding late fees, Alaska's landlord-tenant laws stipulate that any late fees must be reasonable and are typically governed by the terms of the written lease agreement. Alaska Statute AS 34.03.020(b) allows landlords to charge late fees as agreed upon in the lease, but they must not be punitive in nature and should reflect a fair estimate of damages the landlord suffers due to late payment. The implied duty of good faith and fair dealing is recognized in Alaska, as in most states, which means that a landlord's actions, including the imposition of late fees, should be exercised in a manner that is honest and fair. Charging a late fee for rent that is only an hour late could potentially be seen as a breach of this duty, especially if the lease does not explicitly state that rent is due by a specific hour and that time is of the essence.