As part of my work I use the Royal Mail Postcode Address File (PAF) every day.

In theory it is true that with the latest Royal Mail sorting machinery you should only require your house number/name and postcode in order for letters to be correctly sorted and delivered.

However, in reality machines are as subject to error as humans and this only guarantees a 75 to 80 per cent of them actually being delivered.

-Name and address supplied