I want to go home

We're desperate for some new borrower cards. We ordered some only to find that corporate procurement had fallen out with the usual supplier and had decided to go out to tender. After the usual interval, a new supplier was selected; we put in the order, including some blank cards to use as templates and a note of the barcode number we'd need to begin the sequence. After two weeks I got this call:

"These library cards you sent us, they've got different numbers."

"Yes...?"

"You don't want all the cards to have the same number then?"