The Donatists held that all such sacraments were invalid; by their sinful act, such clerics had rendered themselves incapable of celebrating valid sacraments.

The Roman Catholic Church itself recognizes that there are churches not in communion with Rome which possess apostolic succession and thus valid sacraments.

For Lutherans the Eucharist is not considered to be a valid sacrament unless the elements are used according to Christ's mandate and institution (consecration, distribution, and reception).

Most importantly, it clearly states that the Orthodox are "churches" in the full sense of the word, and that they have valid sacraments.

Nevertheless, according to Roman Catholic teaching, the Old Catholic churches of the Utrecht Union have maintained apostolic succession and valid sacraments.

A schismatic church may be recognized as having valid sacraments and clergy.

Catholics are permitted to receive valid sacraments in other churches in similar circumstances of pastoral need.

If a person is in mortal danger and wishes to receive Holy Communion, any Christian is allowed to administer him a valid sacrament.

To be considered a valid sacrament both the appropriate form and matter must be present and duly used.

The question as to who is to be considered the minister of a 'valid' sacrament has led to serious divergences of opinion within Anglicanism.