Is it permissible to give zakat to a person without being certain of their eligibility for it?

It is necessary to investigate when giving Zakat to someone whose entitlement is known or highly probable, and no leniency is permissible in this regard. If one gives it to someone whose entitlement is not highly probable, it is not valid, and they must give it again. Zakat is valid if given to someone presumed eligible after investigation in case of doubt. If it is highly probable that the person is eligible and Zakat is given to them, it is valid.