To use your new AT&T 3G or 4G phone with an AT&T MicroCell, it must be within signal range and added to the approved user list. Note: 2G and non-AT&T devices are not compatible with AT&T MicroCell.
To add a device to your approved user list, from the home screen of the device you set up as the AT&T MicroCell's primary number, tap the Text Messaging icon. Note: You can also add an approved user by logging in at www.att.com/microcell using your myAT&T account information.
Enter the short code 6235 (MCEL) as the recipient of the text message.
In the message field, enter "Add" followed by the number to add to the Approved User List (e.g. Add 5553219876). Then send the text message.
When successfully connected to cell phone will show “AT&T MicroCell” or “AT&T M-Cell”
If you do not see “AT&T MicroCell” or “AT&T M-Cell”, turn your mobile device (not MicroCell) off, wait 10 seconds and then turn it back on. Note: Depending on the signal strength of the AT&T cell tower, the time for your cell phone to switch to the MicroCell can vary. It may take seconds or up to five minutes.