Americans have, on average, more than three credit cards each. Many also have debit cards, flexible spending cards and other accounts that are all associated with a unique 16-digit number that enables transactions.
Plus, most popular virtual payment methods now use so-called tokenization, which means that there are additional unique numbers tied to your account. Each card you have loaded into Apple Pay, for example, is tying up three 16-digit combinations, since the watch and phone each use a unique tokenized number.
"We have way more card account numbers than we ever did before," said Heather McGuire, senior program manager for CO-OP Financial Services, which helps credit unions leverage technology. "You could potentially have four or five different 16-digit account numbers tied to one account."
Ongoing data breaches mean that firms are re-issuing thousands of cards every year and some have also begun issuing different account numbers to joint account holders in order to reduce replacement costs after breaches.
With all of these new numbers, is it possible that we'll eventually run out of unique numbers to use?
"This [question] comes up every few years," said Kris Carrera, senior vice president, financial services product development, global retail payments, at FIS, a financial services technology firm. "But we're not going to run out."