If the wife requests a divorce (khull), does she have to return the dowry to her husband?

If the wife requests a divorce (khull), does she have to return the dowry to her husband as a condition to obtaining the divorce?

If the husband agrees to grant his wife a khul` (a divorce which takes place on the mutual agreement of both spouses), she is not obligated to return her dowry, unless this was the condition upon which the husband agreed to grant the divorce.

For a khul', both husband and wife must come to an agreement on what she is to return to him. The amount she returns can be less than the mahr (to the point where she doesn't return a penny), or the value of the mahr itself; it would be disliked (makruh) for the husband to ask for more than the mahr.

Please see:

Seeking to terminate the marriage through khul`