Register against your school...
..if you are a member of staff at a UK educational establishment. You will be able to order by invoice or credit card and you can sign-up for Collins emails using a school or personal email address.
Register as an individual...
..if you want to set up your account against your personal UK details or a non-UK school/establishment or home address. You will be able to order by credit card and you can sign-up for emails using a school or personal email address.