In Alberta, you do not need a written lease. However, a written lease is a good idea because then both the landlord and the tenant are clear on their responsibilities. If there is a dispute at a later date, having a written lease can help clarify what was agreed to by both sides. A written lease is also important if the landlord chooses to sell the property. The new landlord will have to follow any written agreement that was already in place.
If the lease is in writing, it must contain this statement in larger text than the other text of the agreement: “The tenancy created by this agreement is governed by the Residential Tenancies Act and if there is a conflict between this agreement and the Act, the Act prevails.”
Also, if the lease is in writing and the tenant has signed it and given it back to the landlord, the landlord must give the tenant a copy of the lease with the landlord’s signature within 21 days. If the landlord does not do this, the tenant can withhold rent until a signed copy is received. This is the only time that the Residential Tenancies Act allows a tenant to withhold the rent.