As reported by Nearly Legal concerning section 21 rules the tenant in Spencer v Taylor has been refused permission to appeal in the Supreme Court, because of the lack of an arguable point of law.
Therefore the Court of Appeal decision stands:
“Where an assured Shorthold tenancy has had a fixed term and a statutory periodic tenancy has arisen, there is no requirement to use a section 21 (4)(a) notice, or have a date of expiry at the end of a period of the tenancy. A section 21 (1)(b) notice with two clear months notice is adequate.”
If a tenancy has at some stage had a fixed term then a notice which complies with s21(1)(b) will be an acceptable means of termination either being served during a fixed or periodic part of the tenancy. A notice under s21(4)(a) is only for tenancies that were periodic from the outset and have always been so. Therefore for most tenancies the s21(4)(a) notice is now irrelevant as almost all of them have at some stage have included a fixed term.
However, “Where a tenancy was periodic from the start, or where the tenancy provides for an initial fixed term, then a periodic tenancy thereafter (a contractual periodic) a s.21(4)(a) notice will still be required.”
Further in depth notes on this by Nearly Legal can be seen here