It is one thing to prefer QR codes for mobile payments. It is wholly another thing to actively shut down NFC payment readers.

But that appears to be what Best Buy, 7-Eleven and other members of QR-centric Merchant Customer Exchange, known as MCX, the group of retailers — which now numbers 70 and 110,000 locations — banding together to create a mobile payments network.

According to Computer World, retailers are literally pulling the plug on NFC:

At a Best Buy store located in Harrisonburg, Va., a clerk confirmed that the ability to make NFC mobile payments and related smart card payments at its point-of-sale terminals had been turned off after a directive from the corporate level. A spokeswoman for Best Buy declined to comment.

At one large 7-Eleven store also in the area, a clerk said some of the mobile payment point-of-sale technology had been removed from some checkout counters. …

A corporate spokeswoman said the 7-Eleven app does not currently support mobile payments, but said the app — available for iOS, Android and Windows Phone — does allow customers to redeem coupons and offers by using a barcode on the app that is read by a barcode scanner at the checkout stand.

“We hope to include this [payment] function in the future,” said the spokeswoman, Margaret Chabris.

We wouldn’t call this a death knell for NFC, but it certainly puts ISIS and other NFC-focused mobile wallet providers at a disadvantage. That MCX appears to be picking up steam — it added ExxonMobil to its roster last December — does not help matters.

Computer World asked ISIS, the joint venture of Verizon Wireless, AT&T and T-Mobile US, which finally launched the mobile payment network nationally last November, about MCX’s actions to cut the viability of NFC. Its chief technology officer said it the “handful of retailers” that are “moving counter to the broader industry” are affecting “millions of contactless [smartcards] already in circulation.”

That might be true, but Starbucks, which now generates 10% of its total payments from mobile QR, seems to find wide acceptable for QR, it is difficult to argue for NFC mobile wallet. MCX members process more than $1 trillion of payments per year. In other words, we might be looking at a tipping point toward QR.