On the back of the license there is a 15 digit number part of which is made up of your D.O.B. and the other is the actual license number, it has your name, date of issue and a signature box. I have been checked once by an Environment Agency Bailiff. I was asked to produce my rod license only it was checked initialled and returned I was not asked to produce further identification.
You must always carry your rod license when fishing. It is an offence not to show your license if an Environment Agency Bailiff or a Police Officer asks to see it. You could face prosecution, be fined up to £2.500 and lose your license.
I haven't read in the renewal document or the document the license was attached to anything about having to produce anything other than your rod license/s.