You can offer udhiyah on behalf of the dead: 1- if the udhiyah is offered on their behalf as well as on behalf of the living; 2- if the udhiyah is offered in fulfillment of their last wishes; and 3- . if the udhiyah is offered voluntarily and independently of the living.

The time for offering the sacrifice begins after the ‘Eid prayer on ‘Eid al-Adha and ends when the sun sets on the thirteenth of Dhul-Hijjah.

One sheep is sufficient as udhiyah for one man and his family and whoever he wants among the Muslims. If two or more people buy a sheep and sacrifice it, that is not sufficient.

Sharing in a sacrifice is permissible if it is a camel or a cow, but it is not permissible to share in a sheep. It is permissible for seven people to share one camel or cow.