"Time is of essence and today everyone is pressed for time, beating the traffic, trying to get from one destination to another," said Tigo chief executive Dumindra Ratnayaka.
"This is why we at Tigo try to get as close as possible to our customers by being present at their everyday stopover stops."
Tigo will open customer service centres at fuel stations run by the listed Lanka IOC, a unit of Indian Oil, and Laugfs gas supplier and supermarket chain outlets in and around Colombo.
The services offered include bill payments, pre-paid and post-paid subscription card sales, the sale of handsets, and other services like changing numbers.
Tigo subscribers who use the outlets also stand a chance to win a full tank of fuel or a 5,000 rupee bag of groceries, the company said.
Sri Lanka's mobile phone market has become fiercely competitive where operators are engaged in a price war that has eroded margins of all players.