This is a brief non-comprehensive list of essential landlord requirements when letting property. They apply to ALL types of tenancy unless otherwise stated.
Gas Safety Check
An annual gas safety certificate is required by a gas safe register plumber. A newly installed boiler only requires a certificate within 12 months of the install.
Choose the correct tenancy agreement
Is the tenancy to be an assured shorthold tenancy? The vast majority will be, however, there are a number of tenancies that cannot be AST. These include: Company lets, tenancies where rent is in excess of £25k per annum (£100k from 1 October 2010), lodgers, holiday lets, resident landlords (where landlord lives in one of several converted flats and lets the other flat(s)).
It’s important to remember that when you grant a tenancy, you are giving the tenant “exclusive possession”. Exclusive possession is the ability on the part of a tenant to exclude all persons, including the landlord, from possession. [Street v. Mountford  2 W.L.R. 877]. Although there are certain rights of entry available to a landlord and if a tenant refuses access, they may be liable for certain damages caused (for example if there is a leak and the tenant won’t allow you entry to repair), ultimately, the tenant is entitled to refuse access (by refusing access, this will often be a breach of the tenancy).