Based on the Revolution Money P2P payments platform Amex acquired for around $300 million last year, Serve is already available in the US and will spread to other markets over the next year.

Once signed up, users can an access accounts at the Serve Web site, via Apple iOS and Android applications and through Facebook. Funds are added from bank accounts, debit, credit and charge cards or other Serve accounts.

Money in the account can be used to send and receive funds to friends, pay bills and make purchases online. In addition, to "bridge" online and offline, users are issued with reloadable pre-paid cards linked to their Serve accounts that can be used at merchants and ATMs that accepts American Express.

Customers also have the ability to create, manage, and specify sub-accounts for their friends, family members or colleagues. Sub-accounts are linked to the master and allow users to set spending profiles.

The company has signed up Ticketmaster, Concur and Flipswap as initial commercial partners who will use the platform to deliver offers and is also teaming with five charities on a "giving back" widget.

Amex is waiving fees for the first six months, after which it will cost 2.9% plus 30 cents per load to put money into accounts (discounted to zero per cent for cash, debit and ACH) and $2 for ATM cash withdrawals.

Dan Schulman, group president, enterprise growth, American Express, says: "Serve is a new type of payment platform that isn't tied to a single card or mobile operating system. It's a flexible, easy to use platform, which from day one brings tremendous assets to the alternative payments space and gives consumers an option to shop on-line and off-line at millions of merchants who accept American Express."

The platform sees Amex join fellow card outfits Visa and MasterCard in taking on PayPal in the fast growing electronic and mobile commerce market. The P2P payments space is becoming increasingly competitive, with Visa launching a service last month that lets consumers transfer funds in near real-time to other cards over the VisaNet network.

Discover, by contrast, has aligned with PayPal, tapping its Adaptive Payments APIs to offer card members person-to-person payments. The Money Messenger system lets customers send money to another person via Discover.com or a smart phone using only the recipient's e-mail address or mobile number.