It kicks off on July 1 and provides for minimum revenue payments to Eckoh totalling US$24mln over the term.
Eckoh's hosted products will be made available from October 1 this year via the partner's extensive telephone network, which processes billions of transactions per year.
The US firm's customer base includes over 80% of the Fortune 500 and covers a wide-reaching portfolio of sectors, including financial services, healthcare, retail and telecommunications.
Eckoh has a range of secure payment products that are designed to help merchants become compliant with industry standards.
Interest in this area has grown due to a number of high profile data breaches in recent months.
Echoh's chief executive Nik Philpot said: "Today's announcement represents a significant strategic milestone for Eckoh coming so soon after outlining our US expansion plans.
"Given that our US partner is such a preeminent communications and outsource provider, working with so many large US organisations, we believe they are the perfect partner to help us quickly deliver significant sales growth from the US market.
"Our first mover advantage, combined with the uniqueness and simplicity of our products that will be delivered through a trusted partner, is a combination that we believe US customers will find compelling."
Broker N+1 Singer said: "Eckoh’s products enable organisations to achieve PCI compliance in one of the most challenging areas of “card-not-present transactions” made over the phone and as a result the board believes there are further substantial opportunities for the group."
Eckoh gained 9.45% to stand at 44.875p.