The number of merchant outlets that accept card payments worldwide will likely double from 46.6 million to 90.3 million by 2020, says a recent study from research and consulting company RBR.

According to the study, MasterCard and Visa remain the most widely accepted payment methods globally with 37 million outlets each.

The report, however, raises questions as to whether these two payment giants will be able to sustain this level, since most of the growth will be seen in China, where MasterCard and Visa are accepted at just 29 percent of stores.

MasterCard and Visa acceptance is low in Africa and Middle East, as international sanctions hinder acceptance in the Iranian market, the report noted. Acceptance of these schemes is also relatively low in China.

UnionPay has emerged as the fastest growing payment method in terms of the number of outlets, up 25 percent last year with 5.7 million new outlets. This growth is attributed to UnionPay’s expansion in China, where it added 4.4 million outlets.

Asia-Pacific has seen the fastest growth in the number of merchant outlets followed by central and eastern Europe, the report said.

The addition of contactless technology to EFTPOS terminals has also boosted card acceptance, with contactless card acceptance becoming more common in coffee shops, restaurants, cinemas and pharmacies.

The study also cited MPOS technologies as a potential growth driver in card acceptance.