Hi, thanks for your question. My name's XXXXX XXXXX I'm going to assist you with it.
After the expiry of the fixed term, if the tenant remains in occupation, the tenancy will become a periodic tenancy. If there is no contractual provision for this, it will be a statutory periodic tenancy.
If a tenant wishes to end the period tenancy, he must serve notice. Such notice must (i) be in writing; (ii) give at least 4 weeks notice; and (iii) expire on the last day of the period of the tenancy. This means that if rent is paid monthly on the 15th, the last day of each period of the tenancy would usually be the 14th of the month.
The requirement to give at least four weeks' written notice is provided in s.5 of the Protection from Eviction Act 1977 but this is a minimum, so if the tenancy is a monthly periodic tenancy, a month's notice is required.
Under common law (not statute) a tenant cannot serve notice to end the tenancy in the middle of a tenancy period and the notice must expire at the end of the tenancy period (i.e. before a new tenancy of one month arises). So, for example, if you pay rent on 15th and you want to serve notice on 20th January, such notice must expire on 14th March.
I'm sorry if that's not the answer you were hoping for but I must be truthful so that you understand the position. Can I clarify anything for you?