Originally Posted by
Often1
Of course they should. But, that doesn't absolve individuals of their own duty to check out the codes. Needless to say, OP didn't pick up the phone and ask IHG. Likely because he knew the answer.
But individuals have no possibility to "check out the codes" other than trying to sign up form them to see if they are accepted. And don't tell me that anything else would happen if you'd call the callcenter: they'd input the code and tell you if it was accepted.
HTB.