Users will be able to sync their their Amex cards with Twitter to make purchases by tweeting special hash tags.
The new feature marks one of the most ambitious ecommerce trials yet on a social media website.
Under the arrangement, users will be able to accept offers from merchants by tweeting a hashtag along with the offer. They then musttweet their confirmation to a follow-up message from the payment firm.
Twitter global brand strategy, vice president Joel Lunenfeld, told the Wall Street Journal: "We’re convinced that commerce is going to be one of the areas (for which) advertisers are going to start using our platform."
Twitter also trialled an offer known as ‘Twitsclusives’ that allows merchants to issue discount codes to users that can be used during shopping elsewhere.
American Express Digital Partnerships and Development senior vice president, Leslie Berland, said that based on the initial success of Amex Sync for offers, there is significant power in combining the company’s assets with Twitter’s platform to bring value to Cardmembers and merchants.
"Now, we’re leveraging our unique technology and closed-loop network to introduce a seamless solution that redefines what’s possible in the world of social commerce," Berland said.