When a child or an adult is to be baptized, he or she must have at least one godparent or sponsor (the terms are interchangeable). It is customary for children to have two godparents. When there are two, one must be male and the other female. Godparents must meet all of the following criteria, which are established by universal Church law and which do not vary from place to place. Godparents must:

(a) be Catholic
(b) have been baptized, confirmed and receive Communion
(c) be 16 or older (although there may be exceptions to this rule at the discretion of the bishop)
(d) must be living a life consistent with their own baptismal vows.

This means that they must be practicing the faith, cannot be engaging in notorious sin, and cannot have taken public positions in opposition to Catholic faith or morals. If a sponsor is married, their marriage must be recognized by the Church. In general, if a potential sponsor is not a member of the parish where the baptism is to take place, he or she must obtain a letter or certificate from their own pastor which affirms that they meet the above requirements.

People sometimes object to the requirements for a sponsor. They argue that parents should have freedom to choose the sponsor of a child who is to be baptized. In order to understand the Church's position, several points must be kept in mind.

Baptism is not a private act. It is a public, official liturgy of the Church and welcomes someone into the Catholic Church. Therefore, the Church has the duty and obligation to require reasonable criteria for being a sponsor. The sponsor is to assist the parents and the child in living a Catholic life. In order to do so, the sponsor needs to provide good example of living that life. A person who is not Catholic, or who is not living in a way consistent with the faith, obviously cannot provide the example that is part of the task of being a godparent. The role of godparent is a role of service done in the name of the Church, and the person who is a sponsor should be capable of performing that service.

If there is one godparent, Church law does permit, but does not encourage, the appointment of one 'Christian witness' to the baptism ceremony. This witness must be a baptized, upright, non-Catholic Christian. This 'Christian witness' takes part in the ceremony but is not a godparent. A former Catholic, a non-baptized person, or someone who does not live a virtuous Christian life can never be a Christian witness.