Islamically, Hac is farz (fard) only for those who have reached puberty (bulugh), are of sound mind, and meet other conditions of obligation. A child who has not reached puberty can perform Hac, and it is valid as a voluntary (nafl) act of worship, but it does not count as fulfilling the farz Hac — they must perform Hac again after reaching puberty. Hz. Peygamber Muhammad (sallallahu aleyhi ve sellem) confirmed this when a woman lifted her child and asked if the child could perform Hac.
Saudi Arabia sets its own administrative requirements which may include minimum ages for visa issuance. Children must be accompanied by parents or legal guardians and should be included in the family's Hac application. Some countries have their own age restrictions for Hac registration.
There is no maximum age limit in Islamic law for Hac. However, Saudi authorities may issue health advisories or guidelines for elderly hacilar. Elderly individuals should obtain thorough medical clearance before applying. If a person is too old or ill to perform Hac themselves, they may delegate someone to perform Hac on their behalf (Hac badal), provided they have the financial means. This proxy must have already performed their own farz Hac first.