With the increasing popularity of mobile phones, there is a gradual decline in the coverage rates in landline surveys and these are no longer sustainable. Our objective is to explore various issues that arise with the incorporation of mobiles phones in surveys. We aim at providing researchers with general and practical guidelines. In particular, we focus on legal and ethical issues, and we study coverage, sampling, nonresponse, measurement and adjustment issues. We found important differences in degrees of respondents’ protection between different countries. However, researchers should follow some general ethical guidelines which take this into consideration. Furthermore, we used Eurobarometer data to observe differences in phone use. In some countries mobile phone-only users are prevailing, while in others most people use both mobile and landline phones. We also discuss differences in measurement and nonresponse. Finally, we recommend some weighting approaches that can take into account the differences between the introduced segments (that is mobile, landline and overlap). Despite the strong differences observed from country to country, this work aims at summarizing and integrating various research findings and recommendations that can be widely applied to enhance the quality of collected data and minimize the impact of several of the discussed issues.