When must a woman remove her niqab for ihram during Umrah: immediately upon reaching the miqat, or when preparing for ihram in her home country?

A woman in a state of ihram (definition) is prohibited from wearing the niqab. Therefore, she must abandon it from the moment she enters ihram, whether she assumes ihram from her own country or at the miqat (definition). However, if she does not enter ihram until she reaches the miqat, she may wear the niqab during her journey until she arrives there, because ihram is the intention, and with its presence, the prohibitions of ihram become obligatory.