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 Mississippi, the lease agreement is indeed a crucial document outlining the rights of tenants and the responsibilities of landlords. While oral lease agreements are legally recognized, a written lease provides clearer protection for both parties. It is essential for tenants to thoroughly review and understand the lease before signing. Regarding late fees, Mississippi law does not specify a maximum amount a landlord can charge. However, the lease agreement must explicitly state any late fees for them to be enforceable. Additionally, Mississippi recognizes the implied duty of good faith and fair dealing in contracts, which means that landlords are expected to act reasonably and not exploit technicalities to penalize tenants unfairly. For instance, charging a late fee for rent that is only an hour late may be seen as a breach of this duty unless the lease specifically states that rent is due at a particular time and emphasizes that timing is critical. Tenants should ensure that any terms regarding late fees in the lease are reasonable and comply with this implied duty.