Praise be to Allah.
It is not correct to do ‘Umrah on behalf of one who is physically able to do it himself (if he comes there himself).
With regard to one who is not able to do it for financial reasons, such a person is not obliged to do Hajj or ‘Umrah. Rather it is correct to do Hajj and ‘Umrah on behalf of one who is physically unable to do them, and on behalf of the deceased. And Allaah knows best.