(Bloomberg View) —On a recent trip to Shenzhen, in southern China, I came across a subway busker with two tip jars. The first was a cardboard box filled with coins and bills; the second was a small QR code taped to the box that allowed passersby to leave a tip by smartphone. On one level, this was simply smart business: Chinese made around $5.5 trillion in e-payment transactions last year. But it also offered a glimpse of the future.

Around the developing world, QR codes are beating out Apple Pay and other brand-name payment services for consumers and businesses keen to go cashless. China offers a useful model for that transformation — and a standard that others may soon be emulating.

The QR code may seem like an unlikely candidate to foster a financial revolution. It was developed in the 1990s by Japan’s Denso Corp. after customers grew dissatisfied with the limited amount of information that could be stored using traditional barcodes. In solving that problem, Denso came up with new codes that could be read 10 times more quickly than their predecessors — QR stands for “quick response.”

The technology first caught on in Japan’s automotive industry, which used it to track inventory. But in the early 2000s, Japanese customers began buying feature phones that could read the codes, and marketers began using them to promote websites and products.

By the time Tencent Holdings Ltd. released the social media app WeChat, in 2011, it was clear that QR codes had a lot more potential. WeChat offered users personalized codes that could be used to exchange contact information. When combined with the app’s built-in wallet, they could also be used for payments. Sending money through the app has since become a way of life: During this year’s Chinese New Year holiday, WeChat users sent 46 billion cash gifts via virtual “red envelopes.”

That success shows why QR code payments are likely to take off in emerging markets. For one thing, they don’t require credit cards, which few people in poorer countries have. Apple Pay and other such services, which use Near Field Communication technology, are uneconomical for many of these consumers. (Apple Pay’s market share in China is in the single digits, despite a recent marketing push.) And the small-scale merchants that predominate in the developing world — restaurants, corner markets, buskers — have little reason to invest in expensive payment terminals for the equivalent of $0.50 transactions.

WeChat Pay, by contrast, allows just about anyone with a bank account and a smartphone to make electronic payments. All a Shanghai noodle shop or a Shenzhen busker needs to accept payments is a free WeChat account and a printout of a QR code. Much of China has become a QR first economy, where codes are now found next to nearly every cash register. WeChat’s share of China’s mobile payments market has grown from 3.3 percent in 2013 to 40 percent today.

Other developing countries are starting to see the potential. Last year, MasterCard Inc. rolled out a QR code system in Africa that has already attracted 100,000 Nigerian traders. In February, the Indian government launched IndiaQR, its latest effort to spur a cashless society. Thailand is similarly enthusiastic.

But perhaps the most ambitious step is a new industry standard published last week by EMVCo, a global payments consortium that includes MasterCard, Visa Inc. and the state-backed China UnionPay Co. The effort, spearheaded by UnionPay, would effectively extend China’s payment standard globally, helping to ensure that QR-mediated transactions can flow seamlessly between banks and card companies, while also making them more secure.

That should make the technology more attractive to consumers, merchants and governments around the world. It could help fill the digital tip jars of subway buskers from Shenzhen to Lagos. And it just might make the cashless society a reality far sooner than anyone had predicted.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.