Royal Mail are only responsible for the Postcode and Post Town element of an address.
Royal Mail cannot change the number or name of a building or a subdivision of that building or the name of a street. Only the local authority has the duties and powers to do this.
A postcode is a sorting and routing instruction to enable Royal Mail’s staff to deliver items quickly and accurately. A postcode is not always a geographically accurate description of where a property is located and this may be reflected in the Post Town name used. Postcodes are allocated by Royal Mail under the Postal Services Act 2000.
It is advised that all SNN Officers familiarise themselves with the Royal Mail PAF® Code of Practice which details which elements of an address Royal Mail are responsible for and can change.
http://www.royalmail.com/sites/default/files/Royal-Mail-PAF-Code-of-Practice.pdf