Some documents must be provided by the law:
1) Photo ID, e.g. driver's license, passport, etc.
2) Proof of address, e.g. utility bills within the last 3 months or Pre-registration here: Online Form
The Scrap Metal Dealers Act 2013:
The Scrap Metal Dealers Act (SMDA) 2013 came into force on 1 October 2013, when new licence applications to work as a dealer were first accepted by local councils. The newer Act repealed earlier Acts and created a revised regulatory regime for the scrap metal recycling and vehicle dismantling industries in England and Wales. It is illegal for anyone to buy scrap metal using cash.