What are the duties of a boundary umpire?

Under Law 8.2.2 of the Laws of Australian Football 2026, unless your controlling body (the league or state body) determines otherwise, a boundary umpire's duties include:

1. judging whether the ball is out of bounds or out on the full, and signalling this to the field umpire
2. throwing the ball back into play after it has gone out of bounds, when a field umpire directs you to
3. deciding whether a player has broken a starting position at a centre throw-up (Law 18.2.2(b))
4. bringing the ball back to the Centre Square after a goal is scored
5. reporting a player or official who commits a reportable offence
6. helping the goal umpires determine a score

When you signal out of bounds, the field umpire must blow the whistle immediately to show the ball is out of play.