POSB yesterday launched a scheme which will provide 100,000 commuters with unlimited free travel on the MRT, LRT and buses every Friday until the end of the year.
Fare Free Friday aims to get more POSB customers who hold debit or credit cards that double as ez-link cards to sign up for an automatic top-up service.
While POSB declined to reveal figures, the scheme - which also celebrates Singapore's 50 years of independence - is expected to cost the bank up to $7.5 million.
To qualify, commuters must either have the POSB Everyday credit card or PAssion POSB debit card. They also have to link their cards to EZ-Reload.
EZ-Reload is a service offered by EZ-Link, which automatically tops up a user's card when it has insufficient value.
POSB will also waive the 25-cent convenience fee for every automatic card top-up from now on.
There are currently around 50,000 cardholders on the EZ-Reload service and they will automatically qualify for Fare Free Friday.
The next 50,000 who sign up will be entered into the programme. New card applicants may also apply when they receive their cards.
POSB said that on average, commuters can save around $15 a month and their travel expenditure on Fridays will be returned through rebates in the following month.
Mr Jeremy Soo, managing director and head of consumer banking group in Singapore for DBS - of which POSB is a part - said awareness of the auto top-up service is "not high". It is something the bank hopes to change.
Out of the 900,000 PAssion POSB debit and POSB Everyday cardholders, only 50,000 have activated the EZ-Reload function.
Only about 6 per cent of all top-ups is done through an automatic reload method, according to the Land Transport Authority (LTA) .
Mr Soo said: "There are many commuters out there today who need to queue at the ATM to do a top-up... or they go to the ATM and they withdraw cash, and then go to the GTM (general ticketing machines) to do the top-up ."
LTA chief executive Chew Men Leong said the greater use of auto- top-up services will provide for cashless transactions that are "secure, quick and easy".
"We are also constantly looking at ways to improve the everyday experience of commuters," he added. "We are currently working on contactless payment modes that will allow devices with near-field communication technology, such as wristbands and mobile phones, to be used at the farecard readers."
The LTA is also working on an account-based payment system similar to the post-paid subscription schemes for mobile customers.
Mr Ahmad Jawahir, 61, who works in a mailroom, said: "I do dispatch and I make about five trips a day for work. The free travel on Fridays is good for me."
Administrator Chow Tyan Yih, 29, uses the EZ-Reload scheme with her Citibank SMRT card but also owns the PAssion POSB card.
"I'll use my POSB card just on Fridays, while the rest of the week, my Citibank card," she said, adding the Citibank card also offers rebates.