O2 and Virgin have almost 40 million customers between them, so it will be a huge challenge to bring their records into one platform. Of course M&As have become increasingly common in the telco industry in recent years, and tongues continue to wag about potential activity involving both BT and Nokia over the next few months. Data solutions provider Sagacity work with leading telcos, so I invited Harry Dougall, CFO and founding partner at on the podcast to discuss the typical challenges companies face when merging. We explore some of the mammoth data tasks that could make or break M&As, such as joining all the data together in a unified format. A merger of this scale often takes years, especially if customer information is spread across siloed departments. We talk about the importance of checking for accuracy and records that need to be merged (if somebody was a customer of both organizations). We also discuss how making decisions about which packages are appropriate for which type of customer, where they could be cross-selling services, and identify the most valuable customers to focus on retaining them.