How fast SMS messages get sent are a big deal as these are increasingly used to deliver one-time passwords (OTPs) to secure banking transactions.
The authorities run speed tests for telcos here, though there are no standard requirements.
Since 2007, the Infocomm Development Authority (IDA) has been checking what percentage of SMS messages are delivered by telcos within certain timeframes.
In 2012, this was tightened to 15 seconds, from 20 seconds previously. The independent half-yearly test checks 30,000 sample SMS messages to also measure what proportion of these are delivered within 15 minutes and 12 hours.
An IDA spokesman said the tests serve mainly to provide "competitive pressure" on the telcos to improve their services.
The latest results published on the IDA's website show that more M1 users were able to receive SMS messages within 15 seconds than SingTel and StarHub users.
In the second half of 2012, more than 99 per cent of the messages sent by users of all three telcos were received on M1's network within 15 seconds. SingTel and StarHub scored between 96 per cent and 98.4 per cent.
While most SMS messages are generally transmitted in seconds, they may be delayed when mobile networks are congested or when the recipient's phone has no signal.
The IDA spokesman said SMS networks are not designed to guarantee delivery.
"Operators have no visibility or control over the behaviour of SMS outside their own networks," he noted.
This is partly why security experts say SMS is not a reliable platform for delivering OTP.