T-Mobile expects to save millions of pounds by replacing 20 legacy systems with financial, human resources, supply chain management and business intelligence modules from mySAP.
Early benefits from the deployment of mySAP include streamlined billing and supply chain processes and improved financial reporting, the company said.
Greg Russell, director of financial accounting at T-Mobile UK, said, "The SAP systems deliver the data in real time while it is still current and therefore valuable.
"Our customers are happier because they receive deliveries in just 24 hours. Our customer service advisers are more confident because they know what stock they can promise and our customers are satisfied because they get what they want, when they want it."