Specify mobile telephone numbers
Telephone numbers must be specified in ITU E.164 format. SMS clients are encouraged to store telephone numbers in ITU E.164 international format and use a library to convert ITU E.164-format telephone numbers into a regional, common written format.
The following table is an example:
|Region||ITU E.164 international||Common written format|
United States of America
SMS short codes
SMS short codes that have short phone numbers that are four to six digits long and are typically used to communicate with automated mobile network operator services are supported.