The number of merchant outlets worldwide accepting card payments is set to double from 46.6 million at the end of 2014 to 90.3 million by 2020, states RBR’s new report, Global Payment Cards Data and Forecasts to 2020. UnionPay is the fastest-growing scheme in terms of the number of outlets, having increased by 25% with 5.7 million new outlets in 2014. The main driver of this growth is the expansion of the scheme’s home market of China, where it added 4.4 million outlets. Visa and MasterCard, which are currently accepted at 78% of outlets worldwide, is unclear whether they will be able to maintain this level, as most of the growth will be in China, where they are only accepted at 29% of outlets, it said. Discover’s acceptance network outside of China is significantly smaller than that of Visa and MasterCard. As a result of its scheme-to-scheme agreement with UnionPay, however, its total worldwide network is nearly the same size, the report says.