The currency is the ringgit (MYR). Visa and Mastercard work at hotels, shopping malls and larger restaurants; still carry some cash for small eateries, markets and remote areas. Paying with a foreign card may incur an international transaction fee from your own bank (often around 3%).
Malaysia widely uses DuitNow QR (the pink code). According to Wise (June 2026), DuitNow has integrated Alipay+ for foreign visitors. The Touch 'n Go eWallet is open to tourists from ASEAN countries, including Vietnam, to register (announced May 2025): no Malaysian phone number is needed because verification codes are sent via WhatsApp, and you can top up with a credit or debit card issued by a bank in your home country.
If you want to scan QR codes, download and register the wallet before your trip, then check the latest requirements on the Touch 'n Go website.