This is a Cricket Wireless SIM card that uses AT&T network. You cannot use this SIM directly with AT&T Wireless for an existing AT&T Wireless account or for a new AT&T Wireless account activation. You can only use it for activating your phone with Cricket Wireless (cricketwireless.com) with its own plans, support and customer service.
Cricket Wireless NANO SIM card for AT&T iPhone 5, 5c, 5s, 6, 6 Plus, 6s, 6s Plus, SE, 7, 7 Plus, 8, 8 Plus, X, XS, XS Max, XR phones (AT&T models only and compatible unlocked GSM models only!) activation on Cricket Wireless.
It will work for activating AT&T iPhone 5, 5c, 5s, 6, 6 Plus, 6s, 6s Plus, SE, 7, 7 Plus, 8, 8 Plus, X, XS, XS Max, XR phones with clean IMEI on Cricket Wireless using their bring you own device option
For activation, you will need to go to cricketwireless.com or call Cricket Wireless and buy a prepaid no-contract month-to-month unlimited plan
Before buying, make sure that you have Cricket Wireless coverage and your phone is compatible with AT&T network