1. A customer is defined as a SIM card with a unique T-Mobile USA mobile identity number which generates revenue. Branded contract and branded prepaid customers include FlexPay customers depending on the type of rate plan selected. FlexPay customers with a contract are included in branded contract customers, and FlexPay customers without a contract are included in branded prepaid customers. Additionally, machine-to-machine customers (also known as M2M) are included within contract customers, some of which may not have monthly recurring charges required under contract. Mobile virtual network operators (MVNO) are classified as prepaid customers as they most closely align with this customer segment.

2. Prior quarter amounts have been restated to conform to current period customer reporting classifications.

3. Churn is defined as the number of customers whose service was discontinued, expressed as a rounded monthly percentage of the average number of customers during the specified period. We believe that churn, which is a measure of customer retention and loyalty, provides relevant and useful information and is used by our management to evaluate the operating performance of our business.

4. Average Revenue Per User (“ARPU”) represents the average monthly service revenue earned from customers. ARPU is calculated by dividing service revenues for the specified period by the average customers during the period, and further dividing by the number of months in the period and rounding to the nearest dollar. We believe ARPU provides management with useful information to evaluate the revenues generated from our customer base.

Service revenues include contract, prepaid, and roaming and other service revenues, and do not include equipment sales and other revenues. Data services revenues (including messaging and non-messaging revenue) are a non-GAAP financial measure and are included in the various components of service revenues. Handset insurance revenues are included in contract service revenues.

Branded revenues include contract and prepaid revenues, and do not include wholesale (M2M and MVNO), roaming, other service revenues, equipment sales, and other revenues.