Department of Justice document reveals how long carriers store their customers’ information.
This infographic from Wired shows how long cellular service providers like Verizon and T-Mobile store data about customers’ text messages, IP sessions and calls. For example, text message details (such as names and numbers you’ve exchanged texts with) are kept by Verizon for one year, T-Mobile for up to five years, Sprint for 18 months and AT&T for seven years. This would appear to make Verizon the most privacy-friendly. However, they are the only network that retains the actual content of text messages, storing it for three to five days.
The information was acquired from a Department of Justice document for law enforcement agencies and it shows there is a big difference in the length of time U.S. telecom companies retain data.
Retention Policy (PDF)