Selling to customers in different countries sounds simple until checkout reveals the real complexity — different currencies, card networks, and local payment habits that can quietly kill conversions. This page unpacks what international payment processing actually covers: the difference between an international merchant account and a payment gateway, how a transaction moves from checkout to settlement, and why multi-currency support needs more scrutiny than just a currency list. It also addresses the added underwriting businesses face when they're classified as high risk, plus a practical framework for comparing providers on country coverage, fees, security, and integration. For any company expanding beyond its home market, it's a grounded look at building payment infrastructure that won't need rebuilding at the next stage of growth.