TWINT is the Swiss mobile payment system. Users link the app to their bank account or credit card, or use a prepaid balance, and pay at checkouts, parking meters, vending machines and online shops, or send money to other users. To pay, the customer scans a QR code with the app; NFC is not required. Merchants accept payments via card terminals, a computer or QR stickers for small sellers, and online shops connect TWINT through payment service providers or plug-ins.
TWINT AG is based in Zurich. According to German-language Wikipedia, its shareholders include Swiss banks (BCV, Raiffeisen, UBS and Zürcher Kantonalbank), SIX, PostFinance and the French payments group Worldline with 20 percent; Switzerland belongs to EFTA, not the EU. No US parent company is mentioned. The sources do not say where data is stored, so a European organisation should ask the provider. TWINT is a commercial service and is not open source.