Phone number is the number which is used for outcome and income messages, interaction with customers. By default, your account will be assigned a long/regular code number, but depending on your plans and preferences, you can apply for a short or back to a long code phone number. A long code phone number is used for sendings to both US and international phone numbers, a short code phone number - for US only, but sendings via short code numbers are less limited and faster, for example: SMS - 100 messages per second instead of 1 message per second as via long code MMS - 40 messages per second instead of 1 message per second as via long code
The monthly charge for the selected number will be added to the cost of the subscription. The amount will be charged when the number is assigned and ready for use.
Please remember that if your phone number got changed - you will not be able to get income messages which were sent to your previous number.