Ouch, I don't like the sounds of 'fiddle'!
That aside, don't they cancel the 'original' card? I always assumed they did.
The OP didn't mention which bank it was. If it is one which offers 'tiered' (my word) services depending on income/savings etc, you get the basic card plus the 'enhanced' one if you qualify. The enhanced one allows things like higher daily cash withdrawals, free services, etc. At least one high st bank offers this free.
Of course, there is the question of the other person using the other card. If the account terms say you can't 'loan out' the card, there is a problem.