National Australia bank has launched a new mobile payment service, NAB Pay, allowing customers to use their mobile phones for payments without the need for a payment card.Customers with a compatible Android device and NAB Visa debit card will be able to use the new digital wallet.NAB will also incorporate Visa's tokenisation service, the first Australian bank to use the technology.Tokenisation, which replaces a consumer's 16-digit card number with a unique series of numbers when making a payment, provides additional layer of security for mobile payments. When a consumer makes a payment using a smartphone at a contactless payment terminal, instead of the account number going to the merchant's bank, the token is sent instead.Tokens can be restricted to a specific "use case" or "domain" such as a particular mobile phone. If anyone attempts to use a token in a different domain, the transaction will be flagged as fraudulent and declined.