How to Be a Badminton Line Judge: Signals and Calls

Last updated: July 2026 · Written by the team at Badminton House

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Your Role, Assigned Line, and Chair Position

A badminton line judge has one tightly defined responsibility: decide whether the shuttle landed in or out relative to the line—or lines—assigned to you. Follow that line rather than trying to judge the whole court. Depending on the tournament level, as many as 10 line judges may work around one court, each responsible for a particular boundary.

Your chair should sit in the prolongation of the assigned line: directly in line with the marking so you can look straight along it. The preferred position is opposite the umpire and, where practical, 2.5–3.5 metres beyond the court boundary, protected from spectators or other outside interference.

Before play, confirm both your assigned line and chair position with the umpire during the officials’ briefing. If the singles, doubles, service, or boundary markings are unfamiliar, review this badminton court dimensions and lines guide beforehand.

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The Three Badminton Line Judge Signals

Wait until the shuttle touches the floor. Do not anticipate the landing, then use the signal that matches what you actually saw:

• Out: Call “out” promptly and clearly. At the same time, extend both arms fully and horizontally to your sides, with your fingers together and palms facing toward the court.
• In: Make no verbal call. Point to the assigned line with your right hand, keeping your fingers together and your palm facing down.
• Unsighted: Make no verbal call. Raise both hands separately to cover your eyes, keeping your hands and arms uncrossed.

Use “unsighted” only when your decisive view was genuinely blocked—for example, when a player obscured both the line and shuttle at the landing moment. It is the correct signal when you could not see, but it is not a way to avoid making a close decision.

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Overrules, Unsighted Decisions, and Pressure

A line judge’s factual decision stands unless the umpire is beyond reasonable doubt that the call was clearly wrong. Only then does the umpire overrule it. Where an Instant Review System is available, a player or pair may use the applicable review process; the umpire may also request a review when an unsighted call cannot otherwise be decided.

If your view is genuinely blocked, signal unsighted immediately rather than guessing. The umpire then makes the decision. If neither the umpire nor the Instant Review System can determine where the shuttle landed, the umpire calls a let.

Pressure does not change your task. Sit upright, stay focused on your assigned court and signal promptly after the shuttle touches the floor. Make clear eye contact with the umpire, not the players or spectators. Never anticipate a decision, delay for a reaction or alter your call because someone celebrates, protests or makes a confident gesture.

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What a Line Judge Does Not Decide

Your authority ends with whether the shuttle landed in or out on your assigned line. Service faults belong to the service judge or umpire. Player-contact faults—including a shuttle touching clothing—belong to the umpire, as do conduct faults and lets. Even if you clearly see contact that the umpire misses, do not call the fault; make the normal line decision if the shuttle subsequently lands near your line.

Before your first chair assignment, attend the event briefing and confirm exactly which line you have and which signals are expected. Follow the organiser’s requirements for minimum age, uniform, visible badge, electronic devices and shift timing. These details can vary by event, so do not assume that procedures from another tournament apply.

A damaged shuttle does not automatically remove your responsibility. If it remains in one piece, judge where it lands and give the normal in, out or unsighted signal. The umpire decides whether the rally qualifies as a let.

Rules note: BWF Laws of Badminton and officiating instructions; details verified as of July 2026.

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Which Signal Should You Choose?

Wait until the shuttle touches the floor, then choose among the same three signals using what you actually saw—not how close or difficult the landing looked.

A confident badminton line judge watches only the assigned line, waits for the shuttle to land, and gives the clearest honest signal—even when that signal is unsighted. The umpire may overrule only when a call is clearly wrong beyond reasonable doubt. Confirm your line assignment and signals at the event briefing. We play badminton, so if you need practical advice on choosing match shuttles or planning club stock, contact us.