hey i get INVALID FORMAT on swipe ONLY at a specific store which is my most important store
but the same dumps WORK without any issues anywhere else.
its for swiping GC but the dumps are CREDIT and i think the pos is trying to run it as DEBIT because they only want you to pay via debit....could that be the issue?
has anyone ever seen "DECLINED - INVALID FORMAT" ?

Like you said it might be because they pos is set up for debit cards with pin, also there could be other factors in play like region blocks...

def not region blocks all from same city and state