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 Nevada, the primary source of information regarding tenant rights and landlord responsibilities is indeed the written lease agreement. Nevada law strongly favors written leases for clarity and enforceability. While oral agreements are legal and binding, they can be difficult to prove and enforce, making written leases a more secure option for both parties. Tenants should thoroughly review and understand the lease before signing. Regarding late fees, Nevada Revised Statutes (NRS) 118A.200 allows landlords to charge late fees as specified in the lease agreement. However, these fees must be deemed reasonable and not punitive. The law does not set a specific cap on late fees, but they should be in proportion to the actual costs incurred by the landlord due to the late payment. Additionally, Nevada recognizes the implied covenant of good faith and fair dealing in all contracts, including lease agreements. This means that a landlord's actions, such as charging late fees, should be made in good faith and not in a manner that is unfair or oppressive to the tenant. For instance, charging a late fee for rent that is only an hour late without a clear stipulation in the lease that time is of the essence would likely be seen as a breach of this duty.