Here's why we will never run out of 16-digit credit and debit card numbers

Americans have, on average, more than three credit cards each. Many also have debit cards, flexible accounts and other accounts that are all associated with a unique 16-digit number that enables transactions.

More, most popular online payment methods, so-called tokenization Each card you have loaded into Apple Pay, for example, is tying up three 16-digit combinations, since the watch and phone each uses a unique tokenized number.

"Heather McGuire, senior program manager for CO-OP Financial Services, which helps credit unions leverage technology. "You could have a different type of account."

Ongoing data breaches mean that firms are re-issuing thousands of cards every year and they are also involved in the production of new products.

With all of these new numbers, is it possible that we will eventually run out of unique numbers to use?

"This [question] come 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. "

The potential 16-digit credit card combinations could be used, according to Cris Poor, a mathematics professor at Fordham University. Poor says the 16-digit card numbers have 10 quadrillion possibilities.

By comparison, the world population is a mere 6 billion.

"So many people in the world could have more than a million potential credit numbers, and I do not know anybody who has anywhere near that many credit cards," Poor said.

To understand why we are not going to run out of numbers, we need to know the distribution of credit card numbers.

All card numbers guidelines are laid out by the International Organization for Standardization and the American National Standards Institute, which also sets the standards and size of credit cards. The first digit means the network and industry, so for example, all Visas start with a "4," while AmEx cards start with a "3." That allows the merchants to identify who is responsible for the payment of charges.

The first digit, along with the following, are collectively known as the Bank Identification Number, or BIN. They are assigned to the individual payment networks (Visa, MasterCard, etc.), which then distribute them to card issuers (Bank of America, Wells Fargo, etc.).

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The six digits on every Chase Sapphire card, for example, would be the first six digits of every Capital One Venture Rewards Card. The next nine digits on your card are given to individual users by the issuers, and are unique to your account.

That means that each issuer has millions of individual consumers account numbers that they can distribute.

"Typically," said Lou Grilli, AVP Product Development with Trellance, "has a credit union service organization. "They want to take over some of the re-issue, and for growth or if they decide to add to the family.

"Realistically, they're giving out about 50 percent of their numbers would be acceptable, and they're out there," he added.

Even so, the networks do not want to see their BIN capacity tested. MasterCard BINs are started with the number 5, but in 2017, the network has started issuing a 2 series of cards in order to increase the number of available cards and numbers.

The number of available card numbers is not final, since they can recycle old accounts which have been closed for a certain period of time, issuing them with a new card number and a new CVV (card verification value).

Issuers, which is known as the "check digit." It's calculated via a formula devised by mathematician Hans Peter Luhn. The formula uses the other 15-digits for the card and allows it to be used incorrectly.

There are also several other numbers on your card that help you identify and verify the number. The expiry date and the security code also helps merchants and processors authenticate a card.

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