I arrived in Makkah on the 8th of Thul-Hijjah and then donned the garment of Ihraam (ritual consecration). Am I required to slaughter a sacrificial animal?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Him, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is not permissible for one who intends to perform Hajj or ‘Umrah (major and minor pilgrimage, respectively) to proceed beyond the Meeqaat (certain station from where pilgrims are required to start their Ihraam) except in a state of Ihraam, having made the intention to carry out the rites, and while wearing its garb. A pilgrim who passes the Meeqaat without Ihraam is required to go back and wear it. If he does so, there would be no compensation on him.

On the other hand, if he does not return and rather dons the Ihraam in Makkah, he should repent to Allaah The Almighty for ignoring this obligatory act, particularly if he did not have any valid reason for not going back to the Meeqaat. Furthermore, he is required to slaughter a sheep in Makkah and distribute its meat among the poor in the holy area. By doing so, his pilgrimage would then be valid.

In case he assumed Ihraam [by uttering the Talbiyah (the pilgrimage chant)] from the Meeqaat, but deferred wearing its garment without an excuse, he would be sinful. He would be required to pay a compensation, which is either slaughtering a sheep, feeding six needy people each with half a Saa’ (unit of measurement, which equals about one and a half kilograms, of rice, for instance), or fasting three days. He has the choice to do any of these three options.

However, if he did that due to a [justifiable] reason, such as sickness or the like, he would be required only to pay the compensation and would not incur a sin. Conversely, if that act was done out of ignorance or forgetfulness, there would be neither sin nor compensation on him.

Allaah Knows best.