A business that leases real estate and improvements (buildings, etc.) in the form of space for offices, a warehouse, a restaurant, a nail or hair salon, a clothing store, a coffee shop, or other commercial (nonresidential) space will usually be required to sign a written contract known as a commercial lease agreement.

If the tenant (the business occupying the space) who signs a commercial lease agreement fails to pay the rent on time, the landlord may have the right to charge late fees, terminate the lease, and lock the commercial tenant out of the space by changing the locks.

A commercial landlord’s ability to charge late fees generally depends on the specific language in the written lease agreement 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 commercial 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 Idaho, a commercial lease agreement is a binding contract between a landlord and a tenant for the rental of nonresidential property, such as office spaces, warehouses, or retail locations. The terms of the lease, including the payment of rent and the consequences of late payments, are governed by the specific language of the lease agreement itself. Idaho state law allows landlords to charge late fees if such fees are stipulated in the lease agreement. However, the charges must be reasonable and not punitive in nature. If a tenant fails to pay rent on time, the landlord may have the right to take actions such as charging late fees, terminating the lease, or locking the tenant out, depending on the provisions of the lease. It's important to note that under general contract law principles, which Idaho recognizes, there is an implied duty of good faith and fair dealing in the execution of contracts. This means that a landlord's actions, including the imposition of late fees, should not be arbitrary or excessively punitive, especially if the delay in payment is minimal. The specific timing of rent payments and the importance of timely payments ('time is of the essence') should be clearly outlined in the lease agreement to avoid disputes and to provide clear grounds for any landlord actions taken in response to late payments.