Praise be to Allah.
If the change in your intention from ihraam for Hajj and ‘Umrah together to ihraam for Hajj only happened before entering ihraam, then you do not have to do anything. But if that was after you had entered ihraam for Hajj and ‘Umrah, then the ruling of Qiraan was not waived in your case, so your actions of ‘Umrah are included with your actions of Hajj, and you have to offer the hadiy (sacrificial animal) of tamattu’.
And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.
Standing Committee for Academic Research and Issuing Fatwas
Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan, Shaykh ‘Abd-Allaah ibn Qa’ood.
Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al-‘Ilmiyyah wa’l-Ifta (11/162).