Mobile phone usage is prevalent in Singapore and it is easy to use your mobile phone in Singapore even if it is from a foreign country. You should arrange to have 'global roaming' facilities with your home provider before arriving in Singapore. This will allow your phone to automatically connect with one of Singapore’s networks. GSM900 and GSM1800 are used in Singapore.
Roaming rates will vary from operator to operator so it is best to check beforehand as the rates can be relatively high. A cheaper alternative is to purchase a local prepaid SIM card from the post office or convenience stores like 7-Eleven. This card includes credits which allow you to make calls overseas without paying expensive roaming charges as well as allow for cheap local calls.
There are three mobile phone operators in Singapore: Singtel, Starhub and M1. All offer similar rates. Some tariffs include a charge for incoming calls, so make sure you read the fine print.