Why is my first bill higher?

When activating a new line of service (on a new or existing account), your first bill for that line of service will be for a partial month. This portion is calculated based on the number of days between the date you began service and the last day of the bill cycle. Services are billed in advance so you also will be charged for the next full month. For example, if services were connected on July 15th the August bill would include charges from July 15th to July 31st as well as charges from August 1st through August 31st.