Unlike countries like the United States where phones can be used only with specific carriers, telcos are not allowed to SIM-lock devices that are imported and sold in Singapore. This levels the playing field, and means that telcos compete on their offerings. At the end of a contract, we can move to another telco without having to invest in a new phone. 

Sadly, with some newer phone models, features like 5G and VoLTE (the voice portion of a 4G network) are disabled by default by the manufacturer. To enable these features to work with their network, the telcos need to come to a commercial agreement with the phone manufacturer.

I found this out the hard way when I bought a 5G phone and found that it does not work with my telco. These agreements are specific to each model, so even if the present model of a manufacturer works with a telco, it does not mean that future models from this same manufacturer will work with that telco.

These restrictions are purely commercial and not technical. Is there a database for customers to check which features of which models work with which telcos?

In a situation like this, bigger telcos would be able to offer better terms to phone manufacturers to unlock the features for their network, thus shutting out smaller telcos. We, the consumers, would then be restricted to the telcos that can afford to pay phone manufacturers.

Phua Kok Hee