The demand of mobile service keeps increasing around the world due to the improvement of technology in the telecommunication industry. In order to survive in this stiff competition market, mobile service providers are eager to implement competitive and attractive promotion package in terms of their products and services to attract more customers. This study investigates the factors that affect consumers switching behaviour in the telecommunication industry. A set of questionnaires has been distributed to 200 targeted respondents for the data collection purpose. The data analysis results showed that word-of-mouth and core service failure have a positive influence on consumers' switching behaviour in the telecommunication industry. The data can help marketers have a better understanding of the factors that affect the consumers' behaviour in selecting telecommunication service providers in Malaysia.