If both parties agree to terminate the lease prematurely, it may be terminated. The lease states that no animals are allowed. Is it legal? A lease is advantageous for many reasons. It clarifies the obligations of both parties in a housing rental agreement, so that each person knows what is expected of them during the lease. For example, the tenant may be responsible for paying the rent on the first of each month, while the lessor is expected to keep the property in good condition (dealing with major repairs such as leaks or health problems). Some Alberta organizations have developed leases for the Residential Tenancies Act and provided the forms for purchase. For more information, see our page on forms.