The announcement comes just weeks after the firm revealed it had agreed to sell advertising space for more than 3,000 cash machines in the US and the UK with network operator Cardtronics.
The Fife company, which pioneered the marketing method, secured the contract with a major bank in Ecuador through its partner, Teller Service.
Cash machines at Nationwide branches and Tesco stores already use i-design's software, atmAd, which allows ATM network owners to run third-party advertising as well as their own internal marketing campaigns.
Chief executive Ana Stewart, who founded the firm in 1991, said she hoped the deal would lead to other opportunities in South America.
She said: "This is a strategically important agreement for us, establishing our ATM advertising solution in a major new marketplace, South America.
"We are confident that the benefits of atmAd, which remains globally an unrivalled ATM advertising solution – capable of running on multiple networks – will lead other ATM network owners in South America to explore the opportunity atmAd offers both for market positioning and new revenue generation."