Also known as net-net-net or NNN. A shorthand term for net lease (the purpose of which is to separate out the costs of ownership from those of operating the property) where the tenant pays:

The allocation of costs between the landlord and tenant may vary depending on the negotiated agreement.

Historically, triple net refers to leases where a tenant rents an entire freestanding commercial building and pays for all property expenses. The landlord "nets" the base rent, with no obligation to spend money on property operations.

However, as leasing practices have evolved, and depending on the property's location or local custom, the term triple net lease now also describes leases for a multi-tenant building where each tenant pays its proportionate share of taxes, insurance, and maintenance charges, usually together with other operating expenses (sometimes also referred to as a "proportionate share" or "prorata portion" net lease).

In practice, the terms net lease and triple net lease are often used interchangeably. The parties should not make any assumptions based on how a lease is characterized (net lease versus triple net lease) but must review the lease document to understand the obligations and the expenses for which each party is responsible.