A leasehold which the landlord or tenant may terminate at any time, with reasonable notice, is called:

A leasehold that allows either the landlord or the tenant to terminate the agreement at any time, provided reasonable notice is given, is known as a tenancy at will. This type of agreement is characterized by its flexibility, as it does not have a fixed term or end date, allowing for an indefinite timeframe.

Tenancy at will is particularly useful when a more permanent leasing arrangement is not necessary or when parties desire to maintain the option to leave without significant complications. The requirement for reasonable notice serves to protect both parties by ensuring that no one is abruptly displaced or caught off guard by sudden termination of the lease.

In contrast, a gross lease typically involves a longer-term commitment and stipulates that the landlord covers expenses like maintenance and utilities. A lease for years is defined by a specific duration, such as a one-year rental agreement with a defined start and end date. A term lease, much like a lease for years, also has a predetermined time span, making them unsuitable for the flexibility that a tenancy at will offers.