GSM Frequency Band Guide for International SIM Card Users

When going abroad, frequent international travellers who have an unlocked world phone can take advantage of the low-cost calling and data roaming options that comes with International SIM cards. A world phone is a mobile device that is on the GSM network and supports multiple mobile frequencies. Before going abroad, you should always check that your handset is compatible with the GSM mobile frequency used in the country you are visiting. For iPhone users, you can click here to learn which iPhone model can be used with International SIM cards. 

Mobile Handsets may only be able to receive certain frequencies – the frequencies they use are referred to as bands. There are four different types available, Single Band, Dual Band, Tri-Band and Quad Band.

• Single Band: can only receive one frequency. The frequency depends on the country the handset was manufactured for, for example a Single Band handset for the UK may only support GSM 900, and these handsets are now very rarely used.
• Dual Band: can receive two frequencies. Again depending on the country the handset was manufactured for, the two frequencies may differ. The most common are 900/1800 (UK) and 850/1900 (US).
• Tri-Band: can receive three frequencies. There a two types of tri-band handsets, those which use 900/1800/1900 (European) and those which use 850/1800/1900 (US).
• Quad Band: can receive all 4 frequencies, and will work in most countries.

Important Notice: When travelling to Canada (850/1900), Japan or South Korea.
These countries - networks use 3G service only. A 3G enabled handset is required. Quad Band, Tri-Band and Dual Band GSM handsets WILL NOT work unless they also support 3G. For best results while roaming in USA a 3G Quad Band supporting 1700 MHz handset is recommended.

For full GSM Network Coverage Maps see here

Select Country below for additional information.