September 22, - The notice to vacate letter is provided to give your landlord adequate time to find another tenant for the unit you're vacating. The letter is usually sent out 1 to 3 months before your lease ends. A notice to vacate can be given for any lease length, from month-to-month leases to traditional 1-year leases. Your notice to vacate requirement is generally dictated by your lease agreement. A day. Sample Letter To Landlord Giving 30 Day Notice