Will my mobile phone work in Singapore?
If you want to use your mobile phone and stay socially connected to friends and family when you're traveling in Singapore (or any international country for that matter), you have three options: activate your global roaming option and pay extra fees on top of your regular phone bill, connect to free, local Wi-Fi, or buy a local SIM card.
Once you've figured out which option to go with, you should be able to use your phone in most urban areas of Singapore. If you're venturing into more remote or rainforest regions then you may have limited network coverage and this could affect your phone's ability to send messages and connect to the internet.
Buying a SIM card in Singapore
If you don't like the sound of only having access to the internet when you're connected to free Wi-Fi or paying extra roaming charges then it's extremely easy to buy a local SIM card in Singapore.
Singapore has three main phone providers - Singtel, M1, and StarHub - all of which operate on the GSM network and should be compatible with your unlocked mobile phone. SIM cards from any of the three providers can be purchased at 'Recommends' counters located in all arrival areas in Changi Airport, from currency exchange counters, or from individual telco stores within the airport itself. You can also purchase SIM cards from various phone stores, post offices, or convenience stores in Singapore.
Once purchased, you can easily top up your credit online, via an ATM, or with vouchers previously purchased from phone stores, post offices, and convenience stores.