GSM Frequencies

Before you take your mobile phone abroad with you, you must make sure that it will work in the countries you are planning to visit.

GSM is the digital standard network frequencies used by network operators. There are four major frequencies used across the world: 850 MHz, 900 MHz, 1800 MHz and 1900 MHz. Operators in the UK use either 900 MHz, 1800 MHz or a combination of the two. For example, Orange and T-Mobile work on GSM 1800, whilst O2 and Vodafone work on both GSM 900 and 1800.

In fact, most countries across the world work on 900/1800 MHz. However, the Americas use 850 MHz and 1900 MHz.

Dual Band phones are designed to work on two frequencies; in the UK, these will be 900/1800 MHz. Tri-band phones will work on three frequencies, and tri-band phones in Europe will be set to work at 900/1800/1900 MHz, which means that they can be used in the Americas. A few countries use a frequency of 850 MHz, in which case you will need to use a quad-band phone, capable of working across all frequencies.

The following table illustrates the type of phone that you will need to take if you are travelling abroad: