Two weeks ago, undergraduate Adeline Wong was scolded by a TransCab taxi driver.
She had hailed the cab after clubbing in Zouk. Upon reaching her house in Tampines, she asked the driver if she could pay by Nets.
'I was shocked when he told me he couldn't accept Nets. I thought he was lying,' said Ms Wong, 23.
'Only when he told me that Comfort and CityCab taxis accepted Nets payment did I agree to withdraw money to pay him.'
The cabby drove around the neighbourhood until they spotted an ATM machine - a detour which added $3.60 to the fare.
It is not only passengers like Ms Wong who are frustrated that not all taxis allow Nets payments.
Cabbies are also unhappy.
Mr Ng Eng Soon, 55, who drives a TransCab taxi, said: 'Three out of four of my passengers think they can pay by Nets. I'm so sick of them asking me only after they reach their destination.'
Now, he makes sure his passengers have enough cash before he takes them to their destination.
The Sunday Times understands that ComfortDelGro - which operates Comfort and CityCab taxis - has had a commercial arrangement with the Network For Electronic Transfers (Nets) to provide a cashless service since November 2006.
Nets, owned by banks DBS, OCBC and UOB, has been providing cashless payments for more than 20 years.
According to ComfortDelGro's group corporate communications officer Tammy Tan, Nets payments account for about half of the cashless transactions for its 15,000 cabs.
PAYING WITH PLASTIC
Comfort Taxi (Blue) and CityCab (Yellow)
Fleet: 15,000
All accept Nets and major credit cards.
SMRT Taxis (White)
Fleet: 3,000
About 99 per cent of the cabs accept ez-link payment. Major credit cards are also accepted.
TransCab (Red)
Fleet: 2,600
From the middle of next month, major credit cards will be accepted. It is also considering ez-link payment after credit-card machines are installed in all its cabs.
Premier Taxis (Silver)
Fleet: 2,200
Major credit cards are accepted.
Smart Cabs (Green)
Fleet: 750
About 10 per cent of its taxis accept major credit cards.
Its taxis also accept major credit and corporate charge cards. It has no plans to introduce ez-link payment at this point.
Neither Nets nor ComfortDelGro would comment on whether they have an exclusivity agreement that shuts out other taxi operators, when asked by The Sunday Times.
But Nets did confirm that there has been 'increasing interest' from other taxi operators for a tie-up.
It said it is 'poised to explore any collaborative opportunities', as long as they are 'mutually viable and sustainable'.
But why has that not happened?
All the other five taxi operators The Sunday Times spoke to - Prime Taxi, Premier Taxis, Smart Cabs, SMRT Taxis and TransCab - think Nets has its hands tied.
Premier Taxis, which has a 2,200-strong fleet, said it has been knocking on Nets' doors for the past two years.
A spokesman said it has been given indefinite answers and there was 'no indication of interest' from Nets.
'Many passengers hop onto our taxis thinking that all taxis offer Nets. There have been many cases where taxi drivers had to take them to the police post when they refused to pay or provide personal particulars to the driver,' he said.
TransCab approached Nets in 2006 but was told that the latter could not offer the service as it was bound by an 'exclusivity agreement'. It added that TransCab could try again some time this year, said a spokesman.
Mr Tan Soon Chye, general manager of Prime Taxi, the newest taxi company in the market, said it asked for a collaboration with Nets in January this year.
But it was turned down by Nets, which said its service is 'exclusive' to ComfortDelGro.
Mr Seah Seng Choon, general manager of the Consumers Association of Singapore (Case), said consumers would certainly prefer more payment options since not all carry sufficient cash in their wallets.
He added that it is up to the other taxi companies to approach Nets and explore the possibility.
Case has not received complaints from passengers on the inconvenience of not being able to pay by Nets in all taxis.
The Competition Commission of Singapore said it has not received any complaints of a non-level playing field from taxi operators.