Is expiation required for every oath?

The oath for which expiation is required is the binding oath taken by a legally responsible person, using one of the names of Allah Almighty or one of His attributes, if he breaks it and has not made an exception. If the oath is not binding, or is taken by someone not legally responsible, or is not taken using the names of Allah Almighty, or if he does not break it, or if he has made an exception, then no expiation is required for it.