Warning prompt on text message about additional charges that apply

[AC Question]

I set my text messages to "Never allow" messages to be sent to numbers where additional charges will apply and i would like to reset that option as I now would like to be able to sent text messages to such numbers. Does anyone know how I can reset this? I am using a Galaxy S6 device and the Android version I am on is lollipop 5.1.1 Not sure whether it is a setting on my device or on my account?