Qurbani is Wajib (obligatory) on every Muslim who is:
of sound mind - mature (has reached the age of puberty),
Muqeem (i.e. he is not a Shari traveller)
Possesses the amount of 612,36 grams of silver or wealth equivalent to that value which is in excess of
one's basic needs and debts, on any of the three days of Qurbani. It is not necessary that this amount be in
one's possession for a complete lunar year. (Fatawa Hindiyyah)
1. Qurbani is not incumbent on a child or an insane person whether they own wealth equivalent to the amount above or not, nor is it Wajib upon their guardians to perform it on their behalf. (Fataawa Mahmoodiyyah)
2. Similarly, it is not Wajib on a Musaafir (one considered a traveller in Shariah). A Shar'i traveller is he who proceeds on a journey with an intention of travelling 77 kms. He will be treated as a traveller as soon as soon as he leaves his town. However if he intends residing at any place for 15 days or more then he will cease to be a traveller when he arrives at that location. (Fatawa Hindiyyah)
3. A person upon whom Qurbani is not necessary should not incur debts beyond one's capacity to offer the Qurbani.
4. If Qurbani is not compulsory on a person, for example a Musaafir, then it is virtuous to do so if it is within the person's means.