The largest cellphone company in America, Verizon Wireless, is set to install American Express apps for the credit card issuers new payment service, Serve, on all of their phones and tablets.

American Express and Verizon Wireless have announced the agreement to offer American Express’ Serve payment system on all Verizon mobile phones and tablet devices.

Verizon customers will be able to use the app to create Serve accounts which will function as a digital wallet which can be accessed using their smartphone or tablet. This will allow consumers to receive an offer on their mobile device, accept it immediately and use the Serve app to pay for it.

Serve was launched earlier this year by American Express as a rival to PayPal. It is based on pre-funded accounts which enable consumers to complete online transactions without entering their credit card details.

The partnership will allow Verizon customers to link the Serve app to their bank account or credit card and make payments or redeem special offers online or straight from their mobile phone. Customers will also receive a prepaid, reloadable debit card linked to their serve account which can be used anywhere that American Express is accepted.

In addition, American Express and Verizon also announced that they have teamed up to source, distribute and simplify redemption of online and mobile offers with participating merchants through the use of the Serve accounts.

An American Express spokesperson, Dan Schulman, group president of Enterprise Growth, said,

Our collaboration with Verizon highlights the speed at which Serve is evolving to reach a wide audience. Verizon Wireless customers will soon be able to complement their busy lifestyle with a trusted payment platform that delivers a fast, flexible and secure way to manage their day-to-day mobile purchases, and together we’re taking the necessary steps to make mobile commerce a reality.

This latest partnership with Verizon is another step by American Express towards digital and social media. The credit card issuer also announce two programs linked to Facebook earlier this year. The “Link, Like, Love” Facebook application allows card holders to receive cardholder discounts based on their interests and social connections. For example, if a cardholder ‘likes’ a particular restaurant’s Facebook fan page, they may receive a discount for 10 percent off their next meal at the restaurant.

In addition, American Express rolled out a program allowing cardholder to redeem reward points to buy Facebook advertising credits. The company has also teamed up with Foursquare to offer a mobile discount program.