Section 20 notice
These only apply to tenancies granted prior to 28 February 1997. Landlords applying for possession using the Section 21 can ignore this if their tenancy commenced after this date.
It is necessary to serve a special notice (called a Section 20 notice, because it was required by section 20 of the Housing Act 1988) on a tenant, before a tenancy was created, if you wanted that tenancy to be an AST. This has caused many problems for inexperienced landlords, as the notice had to contain certain prescribed information and was invalid if it did not. Once a tenancy had started, it is impossible for it to be converted to an AST if a Section 20 notice had NOT been served or if the notice served was defective.
Section 20 notices are no longer necessary for new tenancies as they were made redundant by the Housing Act 1996, which came into force (so far as Section 20 notices were concerned) on 28 February 1997. Section 20 notices are still important however, for tenancies created between 15 January 1989 and 27 February 1997.