Will I get charged for calling a US mobile number which is abroad?

The caller will not incur any international charges calling your number. Only the phone that is roaming is subject to international roaming charges. It does not matter whether you are on WiFi calling or not, the caller will not be charged. To them it is the same as calling your number when you are in the US. 

Hi lavigne42, let's answer your International long distance dialing and texting inquiries!

International dialing billing scenarios

• A customer in the United States (U.S.) dialing another U.S. number isn't charged for international dialing rates, even if the person they are calling has traveled outside of the U.S.
• A customer in the U.S. dialing a non-U. S. number is charged international long distance rates as applicable to their service and has airtime deducted from their current rate plan based on Airtime Billing Priority.
  • Applies even if the non-U.S. number is in the U.S. at the time of the call.
• A customer in the U.S. receiving a call from an international number has airtime deducted from their current rate plan.

How is a customer charged when traveling internationally and receiving a text from someone in the U.S.?

• Customers traveling internationally receive text, picture, and video messages at domestic rates.
• No extra charges apply to receiving a message.
• Since friends and family back home are sending messages to a domestic number, they send text, picture, and video messages at domestic rates, as well.
• Customers travelling outside the country who are sending messages back in the U.S need an international plan for text messaging. International Day Pass(IDP) includes text messaging. 
• A complete list of discounted countries and rates is available by visiting att.com/international.

If you need additional help, please create a new post since this is an old thread and is subject to be closed at anytime. 

We hope this helps, thank you for reaching out to the AT&T Community Forums!

Rhoda, AT&T Community Specialist