§1. Without prejudice to the right of religious mendicants, any private person, whether physical or juridic, is forbidden to beg for alms for any pious or ecclesiastical institute or purpose without the written permission of that person’s own ordinary and of the local ordinary.
§2. The conference of bishops can establish norms for begging for alms which all must observe, including those who by their foundation are called and are mendicants.
Source: Code of Canon Law (Vatican.va)