Golf is open to all
No sharing of clubs
You must not make a stroke with a club being used by anyone else who is playing on the course (even if the other player is playing in a different group or competition).
When you become aware that you are in breach of this Rule by making a stroke with another player’s club, you must immediately take the excess club or clubs out of play. To do this, you must take an action that clearly indicates each club that you are taking out of play before making your next stroke (such as by advising another player or turning the club upside down in your bag).
But in partner forms of play, you may share clubs with your partner if you have no more than 14 clubs between you.
Follow the link below for details of the penalty that applies if you breach this Rule.