All tenancies (including renewals but not tenancies that continue on a statutory periodic basis) that started after the 1st October 2015 are now subject to new regulations associated with the service of Section 21 notices.
You must provide your tenants with the following documents at the commencement of the tenancy:
A copy of the AST
A valid gas safety certificate (CP12)
A copy of the EPC
You are not able to serve a valid Section 21 notice if you have not provided your tenants with these documents. It is strongly recommended that you retain evidence that these documents have been provided to your tenants.
You can no longer serve a Section 21 notice in the first 4 months of a tenancy (or any subsequent renewal).