Except for a tenancy taking effect in possession with a term not exceeding 3 years [s.2(5)(a) Law of Property (Miscellaneous Provisions) Act 1989],  a contract for the disposition of an interest in land (which includes tenancy agreements) can only be made in writing and only by incorporating all the terms which the parties have expressly agreed in one document or, where contracts are exchanged, in each [s.2 Law of Property (Miscellaneous Provisions) Act 1989]. Such a document must be made as a deed.