Validity of Hole in One
What constitutes the validity of a hole in one?
The Rules of Golf do not address the issue of the validity of a hole-in-one. It is up to the Committee to determine whether a hole-in-one is valid.
The USGA recommends that a hole-in-one be considered valid:
If made during a round of at least nine holes, except that a hole-in-one made during a match should be acceptable even if the match ends before the stipulated round is completed.
If the player is playing one ball; a hole-in-one made in a practice round in which the player is playing two or more balls should not be acceptable.
If attested by someone acceptable to the Committee.
If made at a hole with a temporary tee and/or putting green in use, even if the Committee did not specifically define the teeing ground with tee-markers; the length of the hole at the time should be stated on any certificate.
If made in a "scramble" competition, which is played as follows: A side comprises four players. Each member of a side plays from the teeing ground, the best drive is selected, each member plays a second shot from where the best drive is located, and so on.