Local telcos defended their policy of offering 4G services as an "add-on" to 3G services yesterday, claiming it offers customers flexibility.
It came after StarHub announced plans on Tuesday to start charging for the 4G add-on, which it currently offers for free - as do SingTel and M1.
Few other countries operate such a system and an online poll of almost 1,000 people by The Straits Times last night revealed that close to 90 per cent of all mobile users thought that they had already bought a 4G mobile plan and did not know 4G service was merely an extra with a 3G plan.
StarHub claimed that free 4G access was a promotion with an expiry date, as indicated in its brochures and on its website.
Its assistant vice-president of mobility Tian Ung Ping said 4G was a new technology when it was first launched two years ago.
As of June, his customers will have to pay $2.14 a month for its 4G "Speed Boost" add-on that allows surfing at up to 75Mbps - twice as fast as 3G.
Customers can choose to pay up or opt out.
Mr Tian said the option gives them "the flexibility to experience the latest technology amid a limited choice of supported handsets".
"We have evolved and will continue to evolve in the way we package our services," he added.
Rival telcos SingTel and M1 also provide 4G services as an add-on and are also expected to follow suit and start charging for them.
The latter also cited flexibility as the key reason for providing 4G services as an add-on and said the terms were clearly explained in its marketing materials. M1 said its promotion will end on Dec 31.
Meanwhile, a SingTel spokesman said that if it were to change its price plans or promotions, the changes would apply only to new or re-contracting customers. The company would only say its promotion would end at "a date SingTel determines".
However The Straits Times poll suggested that customers did not appreciate the "flexibility".
Asked if they prefer separate 4G plans - even if these prove more expensive than 3G ones - more than 80 per cent of mobile phone users gave the answer: "Yes, so that there are no price changes mid-way through my contract."
In markets like Hong Kong, Australia and Britain, 4G plans are priced separately from 3G plans.
Mr Clement Teo, Singapore telco analyst for US-based market research firm Forrester, questioned the methods of telcos here: "Were 3G services in Singapore also sold as an add-on to 2G plans? I don't think so."
Consumers Association of Singapore executive director Seah Seng Choon urged telcos to honour the price promoted at the point of sign-up for the whole duration of the customer's contract.
Businessman and M1 customer Harry Chew, 44, said that changing 4G terms while contracts are still in force is akin to pay-TV operators unilaterally removing channels or programmes and imposing higher fees. "I won't sign a contract next time," he said.
Businessman Koh Wei Ming, 30, said customers had a right to feel "cheated" by the plans.
Regulator Infocomm Development Authority said that while telcos may change service agreement terms, they must give "reasonable advance notice". If price increases are not indicated during sign-up, telcos are not allowed to change the terms of customers on contracts.