Check which of the following best describes your scenario.
You have activated Caller Number Non-Display (CNND) feature
Some countries will not connect through calls if you have blocked the Caller ID. You must deactivate it first by dialling #331#.
Dialling Singtel IDD access codes does not work
You need to pre-register with the other telco operator before you can call through their network.
You have trouble using other telco operator's access codes
You will need to pre-register with the other telco operators' by calling their respective hotlines.
You hear the announcement “Sorry, you have not entered the correct PIN. Please try again”.
You have subscribed to the PhoneLock service and your phone is blocked from making IDD calls. Dial the code #570 followed by your PIN and #, to deactivate the feature, i.e. #570PIN#.
