Corporate heavyweights don’t come much bigger than Visa, MasterCard and Amex — unless they’re Walmart and Home Depot or AT&T and Verizon.

Now those two latter groups — the big box retailers and the mobile phone carriers — have set out to muscle their way into the payments business long controlled by the purveyors of plastic. It’s all part of the revolution in how we pay, made possible by smartphones.

“The digitalization of money is a great leveler,” said Nick Holland, ‎a senior payments analyst at Javelin Strategy & Research. “The way that CDs have gone to MP3s and photos have gone digital, the payments industry is at an inflection point where there is the potential for the old guard to get cut out of the equation.”

But the old guard won’t be cut out willingly.

The stakes are huge and the players are motivated, so expect the battle to be intense. And as for us consumers? How will this affect our lives?

You may read the full story — and the first two installments in the Future of Money series — at myajc.com.