Originally Posted by invisible

You should not have a problem using your US-issued credit cards everywhere in Singapore with few exceptions. As I have been doing for 10 years.

These few exceptions are AXS and SAM kiosks, which to you, as a visitor, are most likely irrelevant.

The third well-known exception is Translink GTMs (General Ticketing Machines) in all MRT stations. Before Feb 2020 it was possible to top up Ezlink and NFP (Nets FlashPay) cards using non-Singapore issued cards but they restricted it in Feb 2020 and it has been since that and there is no workaround directly (*). Chase is right - they don't even see the transaction coming to them because it is blocked by the merchant (Translink)

You can use your Contactless Visa/MC cards directly at buses and MRT stations by tapping them in and out, but it requires to download SimplyGo app and register/enter your card number in that app. After 24h you can use the card. The catch is that the system will add 50c on any ride for the foreign-issued card. So if your ride is $1.10, you will be charged $1.60.The same applies to using Apple Pay/Samsung Pay/Google Pay - you can use your mobile phone for tapping in/out and in this case, won't even need to register your card with SimplyGo app, but you will pay 50c surcharge regardless.

(*) the one workaround to top op NFP cards using foreign-issued credit cards was to get NFP android app and on NFC enabled higher-end Android phones (like the Samsung S series) use the app to top up the card. The app charges 1% surcharge, so for $50 you will pay 50c surcharge and have $50 in your NFP card, but this method is still better then paying 50c every time.