I assume this promo is aimed at hbos group customers of which i am one.

Here id the NPN  entry route details:
3. Upon signing up for our Paper-free service, you will be automatically 
entered into the draw.  If you do not wish to enter via this method, you can 
send your name and address to be received by 31st May 2005, to HBOS plc, 
Paper-free prize draw, 6th Floor Computer Building, Trinity Road, Halifax 
HX1 2RG to be entered into the draw.