Landlord and tenant – Tenancy. The tenants had paid a deposit for a property under the terms of their tenancy agreement. Subsequently, the statutory tenancy deposit scheme was introduced, but the deposit was never placed in such a scheme. The landlady purported to serve notice to quit under s 21 of the Housing Act 1988 and the tenants challenged the validity of that notice because of the failure to comply with the statutory deposit scheme. The Court of Appeal, Civil Division, held that s 215 of the Housing Act 2004, as amended by the Localism Act 2004 and enacting Order, had not been retrospective in their operation and, since the tenants' deposit had never been kept in an authorised scheme, the possession notice had been invalid.