How to Referee Badminton
Umpire Duties, Service Faults, Let Calls, the Hawk-Eye Challenge System & Path to Certification
Last updated: April 6, 2026
Badminton officiating uses a structured crew: the umpire sits on a raised chair at the net post with overall match authority, a service judge watches specifically for service faults, and line judges (8-10 at major events) call in/out decisions. Players get one unsuccessful Hawk-Eye challenge per game at BWF World Tour events. The referee oversees the entire tournament and handles appeals beyond the umpire's authority.
Official Roles: Who Does What on the Badminton Court
A standard BWF World Tour match uses the following officiating crew:
Umpire The umpire sits on a raised chair at the net post, providing an elevated view of the entire court — similar to a tennis chair umpire. The umpire has overall authority over the match and is responsible for:
- Calling the score after each rally
- Calling faults (except service faults, which the service judge handles)
- Announcing the start and end of games and the match
- Managing intervals (60-second mid-game, 120-second between games)
- Calling lets (replayed rallies)
- Overruling line judges when clearly confident a call was wrong
- Managing player conduct and issuing warnings/penalties
- Communicating with the referee on disputed matters
Service Judge The service judge sits in a low chair on the opposite side of the net from the umpire, close to the net. Their sole focus is monitoring the legality of the serve:
- Shuttlecock struck below 1.15m from the court surface
- Racket shaft pointing downward at moment of contact
- Server's feet stationary and within the service court
- Shuttle contacted below the hand holding the racket
- No undue delay in the serving motion once started
The service judge signals a fault by raising the right hand, and the umpire then announces the fault and awards the point to the receiving side.
Line Judges (8-10) Line judges are positioned around the court perimeter, each responsible for one or two specific boundary lines. At major events, 10 line judges cover all lines. At smaller events, 4-6 line judges may cover multiple lines each.
- In: Arms extended and hands pointing down toward the court (or toward the line)
- Out: Arms extended horizontally to the sides, palms outward
- Unsighted: Both hands placed over the eyes — indicates the line judge could not see the landing
Referee The referee is the overall tournament authority — not a court official. They oversee all matches, handle appeals, interpret rules, and manage disciplinary matters that exceed the umpire's authority. The referee can overrule an umpire's decision only on a question of law (rule interpretation), not on a question of fact (judgment call).
| Role | Position | Primary |
|---|---|---|
| Umpire | Raised chair at net post | Overall match authority — calls score, faults (except service), manages play |
| Service Judge | Low chair, opposite side of net | Monitors service legality — height, racket angle, foot position |
| Line Judges (8-10) | Around court perimeter | Call shuttlecock in/out on assigned boundary lines |
| Referee | Tournament-level (not on court) | Overall tournament authority — appeals, rule interpretation, discipline |
Service Faults: The Most Common Calls in Badminton
Service faults are the most frequently called violations in badminton and have been the subject of major rule changes. Understanding them is essential for any official.
Height fault (the 1.15m rule): Since March 2018, the BWF requires that the entire shuttlecock be below 1.15 meters from the court surface at the moment of contact. This replaced the old 'below the waist' rule, which was subjective and difficult to enforce consistently (players' waist heights vary). The fixed height is measured using a device or reference marker on the net post. At events without the measuring device, the service judge must estimate.
Racket angle fault: At the instant of hitting the shuttlecock, the shaft of the racket must be pointing in a downward direction. This means the racket head must be discernibly below the server's hand holding the racket. This rule ensures the serve is genuinely underhand.
Foot fault: Both the server and the receiver must have part of both feet stationary on the court surface in the proper service court until the serve is delivered. The server cannot step, shuffle, or drag their feet during the service motion. A foot touching a line of the service court is a fault.
Feinting fault: The server must not make any feinting movement that is intended to deceive the receiver. Once the server begins the forward swing toward the shuttlecock, the motion must be continuous — the server cannot stop, hesitate, or fake a serve.
Delay fault: Once both server and receiver are ready and the server has started the motion, there must be no undue delay in delivering the serve. The server cannot hold the racket back indefinitely to unsettle the receiver.
Let Calls: When a Rally Is Replayed
A 'let' in badminton is a call that stops play and requires the rally to be replayed with no point awarded. Lets can be called by the umpire or, in some cases, requested by a player.
Mandatory lets (umpire must call):
- The server serves before the receiver is ready. If the receiver attempts to return the serve, they are considered to have been ready.
- During the service, both the server and receiver commit a fault simultaneously.
- The shuttlecock gets caught on top of the net after crossing it — it passes over the net but remains suspended on the net tape.
- The shuttlecock disintegrates during play — the cork base separates from the feathers (this occurs with feather shuttlecocks).
- A line judge is unsighted and the umpire cannot make a definitive call.
Discretionary lets (umpire's judgment):
- An unforeseen or accidental situation occurs — for example, a shuttlecock from an adjacent court enters the playing area, or a significant external disturbance (loud noise, object falling onto court).
- The umpire believes a player was genuinely distracted by an event outside the match.
Important: A let is never called for a player's own unforced error, clumsiness, or misjudgment. The let system exists solely to handle situations where fair play would be compromised by replaying the rally.
Hawk-Eye Instant Review System
The BWF has adopted the Hawk-Eye instant review system at World Tour Super 1000, Super 750, Super 500 events, World Championships, and Olympic Games. The system allows players to challenge line calls.
How many challenges? Each player (or pair, in doubles) receives one unsuccessful challenge per game. If the challenge is successful (the line call is overturned), the challenge is retained — the player does not lose it. If the challenge is unsuccessful (the original call stands), the challenge is lost for the remainder of that game. Challenges reset at the start of each new game.
What can be challenged?
- Line calls — whether the shuttlecock landed in or out of the court boundaries.
- This includes the service line (short service line, long service line, center line, and side lines).
What cannot be challenged?
- Service faults (height, racket angle, foot position) — these are the service judge's judgment calls.
- Net touches, lets, and other umpire judgment calls.
- Conduct violations or penalties.
Challenge procedure:
- The player raises their hand and calls 'Challenge' or 'Review' immediately after the line call — before the next serve.
- The umpire announces the challenge to the crowd.
- The Hawk-Eye system replays the shuttlecock's trajectory on the court screen, showing the exact landing point with millimeter accuracy.
- The umpire announces: 'Challenge successful — the shuttle was [in/out]' or 'Challenge unsuccessful — the original call stands.'
Accuracy: Hawk-Eye uses multiple high-speed cameras to track the shuttlecock and produce a 3D reconstruction of its flight path. The system's accuracy is typically within 2-3 millimeters, making it extremely reliable for close line calls.
At events without Hawk-Eye: The umpire's decision (or the line judge's call, as upheld or overruled by the umpire) is final. There is no challenge system at lower-tier events.
Common Faults and Violations During Play
Beyond service faults, the umpire must watch for several in-play violations:
Net fault: A player or their racket touches the net or net supports while the shuttlecock is in play. This includes touching the net during a follow-through after a shot. The moment the shuttlecock hits the floor or a fault is called, net contact is no longer penalized.
Invasion fault: A player's racket or body crosses the net into the opponent's court during play. The racket may cross the net on the follow-through after hitting the shuttlecock (as long as the initial contact point was on the striker's side), but no part of the body may cross under the net and interfere with the opponent.
Double hit: The shuttlecock is struck twice in succession by the same player, or is struck by a player and their partner successively (in doubles) before crossing the net. A single swing that contacts the feathers and then the cork (or vice versa) is considered a single hit and is legal.
Shuttle caught on racket: The shuttlecock is caught and held on the racket during a stroke (a 'sling' or 'throw'). The shuttlecock must be hit with a clean, sharp contact — not scooped or carried.
Obstruction: A player deliberately obstructs or distracts an opponent by any action such as waving the racket, shouting, or blocking the opponent's view of the shuttlecock.
Receiver movement on serve: The receiver moves before the server strikes the shuttlecock. Both server and receiver must remain stationary until the serve is delivered.
| Fault | Description | Consequence |
|---|---|---|
| Net fault | Player or racket touches net while shuttle is in play | Point to opponent |
| Invasion | Racket or body crosses net into opponent's side (body contact or interference) | Point to opponent |
| Double hit | Shuttle struck twice successively by same player or both partners before crossing | Point to opponent |
| Sling/throw | Shuttle caught and held on racket — not a clean hit | Point to opponent |
| Obstruction | Deliberate distraction of opponent through actions or noise | Point to opponent (may also incur conduct penalty) |
Player Conduct and Disciplinary Sanctions
The BWF has a structured system for managing player conduct during matches:
Misconduct categories:
- Delaying the game — taking excessive time between rallies, deliberately slowing play
- Deliberate distraction — shouting, gesticulating, or making movements intended to distract the opponent
- Offensive behavior — verbal abuse, obscene gestures, racket abuse (throwing or smashing the racket)
- Coaching violations — receiving coaching outside the permitted intervals (coaching is allowed during the 60-second and 120-second intervals only)
Penalty progression:
- Warning — the umpire issues a verbal warning. For a first minor offense.
- Fault — the offending side loses the rally (a point is awarded to the opponent). For repeated or more serious misconduct.
- Match referee involvement — for persistent or severe misconduct, the umpire reports to the tournament referee, who may issue further sanctions including match default (disqualification).
The continuous play rule: Badminton enforces a strict continuous play requirement. Players must not delay between rallies except during permitted intervals. The umpire can call a fault for deliberate delay. This rule keeps matches flowing and prevents gamesmanship.
How to Become a Badminton Referee or Umpire
Badminton officiating certification is managed through national federations affiliated with the BWF. The pathway is structured in levels:
Level 1 — Club/Regional Umpire:
- Entry-level certification through your national badminton federation (e.g., Badminton England, PBSI in Indonesia, PZBad in Poland)
- Requirements: rules knowledge course, written examination, practical assessment (umpiring matches under supervision)
- Allows officiating at local leagues, club tournaments, and regional events
Level 2 — National Umpire:
- Requires Level 1 experience (typically 1-2 years with a minimum number of officiated matches)
- Additional training covering advanced rules, match management, and conflict resolution
- National-level written and practical examinations
- Allows officiating at national championships and higher-level domestic events
Level 3 — Continental/International Candidate:
- Requires strong national-level track record and recommendation by the national federation
- Continental badminton confederation assessment (e.g., Badminton Europe, Badminton Asia)
- Advanced video-based rules assessment
BWF Accredited Umpire:
- The highest level, governed by BWF directly
- Requires nomination by national federation and continental confederation
- Attendance at BWF Umpire Assessment at designated international events
- Comprehensive practical and written evaluation
- BWF-accredited umpires officiate at World Championships, BWF World Tour, and Olympic Games
- Must maintain active status through regular officiating and periodic re-accreditation
Getting started: Contact your national badminton federation — most offer introductory umpire courses, often online or at weekend clinics. Many federations actively seek new officials and provide financial support for training and travel.
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