Scanning a QR code to order and pay for food is now commonplace at restaurants in China as it boosts efficiency by saving time and resources, including manpower.

Most eateries have quickly adapted to this digital transformation and some have completely done away with printed menus and conventional payment methods, triggering dissatisfaction among a section of customers such as the elderly who are not very tech-savvy.

While the adoption of QR codes may be particularly appealing to Generation Z and millennials, the digital leap has raised concerns of a privacy breach as it is often mandatory to log in to the account of a restaurant using a phone number or WeChat.

In Shanghai, an elderly couple was recently turned away from a restaurant because they didn't have smartphones to scan the QR code.

The husband, surnamed Xia, told Shanghai-based Xinmin Evening News that when they went to a Kwei Mun Lung restaurant, a waiter asked them to scan the QR code at their table to place an order. When they said they were not tech-savvy, a second waiter told them scanning the code was the only way to order food. The couple left the restaurant disappointed.

"We are just too old for all that. We pay in cash for groceries, subway rides and meals," Xia said, adding that he and his wife, who are in their 80s, do not own mobile phones that can scan codes.

A field visit by Xinmin revealed that every diner had to agree to terms and conditions, register online as a member with the said restaurant and then place an order using the QR code.

Waiters confirmed that the restaurant did not offer printed menus, and scanning the code was the "only way" to order. The chain's other restaurants in Shanghai all have the same policy, they said.

On Thursday, the Kwei Mun Lung restaurant chain issued a statement on its social media account and apologized for the inconvenience it caused to the couple. It said it has equipped all its eateries with printed menus and waiters will help diners order in the conventional way.

The statement further said that diners will not have to provide their personal information for membership or follow the restaurant's social media account if they ordered food using the "voluntary "QR code scanning method.

Magnifying glasses will be provided to elderly customers or those who have trouble reading the printed menu, it added.

Luckin Coffee, a nationwide beverage chain, requires its customers to order via QR code or its mini app, which stores personal and shopping information, according to a report by Southern Metropolis Daily. Servers at Luckin Coffee outlets said the system has been in place for more than a year.

Lawyers and market inspectors called the practice of compelling customers to use digital ordering and payment services "unlawful".

"It infringes upon consumers' right to choice and fair trade," Qin Yubin, a senior partner at Shanghai-based Shangfa Law & Consulting, told Xinmin. "In addition, the practice is also likely to have obtained consumers' personal information beyond reasonable need. There is no need to register a cellphone number if it is just about ordering a meal."

In 2021, the Shanghai Administration for Market Regulation imposed a fine of 50,000 yuan ($7,000) on a catering company for illegally collecting consumers' personal information by requiring them to order through a QR code. Last year, the administration listed the case as an exemplary one in protecting consumers' rights.

Market regulators said the company unnecessarily collected mobile phone numbers, did not inform consumers about its purpose, ways and scope of using those numbers, and did not protect their privacy by encrypting its database.

"Customers should say 'no' to these businesses. ... and these vendors should rectify their behavior if they really care about consumers' rights and conveniences," Qin said.

The China Consumers Association said on Monday that it will launch a nationwide campaign against the practice of forcing consumers to follow the social media accounts of merchants while shopping.

The association encouraged consumers to report such cases so that it could take corrective measures and, if necessary, press civil lawsuits against merchants.