Challenge immediately; only failed challenges reduce the allowance.
Published
On a court where the authorised Instant Review System (IRS) is operating, a player or pair may immediately challenge a line judge's call, an in-or-out call made by the Umpire, or the Umpire's overrule. IRS then reports IN, OUT or NO DECISION; it is not a general replay system for other faults.
Quick ruling: BWF Statutes Section 4.1.8, in force 11 November 2023, Version 2.0, permits unlimited challenges until the player or pair has two failed challenges in that game. A successful challenge, an Umpire-requested review, a “No Decision” or a malfunction does not consume a challenge right. BWF Law 17.5.2, Version 5.0 in force 26 April 2025, makes IRS decisive unless its result is inconsistent or obviously incorrect.
At a glance
How the challenge process works
A line judge or Umpire makes an in-or-out decision, including an Umpire overrule.
A player immediately says “Challenge” to the Umpire and/or clearly raises a hand.
The Umpire checks that the player or pair still has the right to challenge.
The Umpire identifies the player in an individual tournament, or the team in a team tournament, states the original call, and signals the review request.
The system returns IN, OUT, or NO DECISION.
The Umpire announces the resulting decision, updates the score or service as necessary, and resumes play.
Scope
This is the BWF baseline, and it applies only on an IRS court
This page uses the BWF Laws of Badminton, Version 5.0, in force 26 April 2025; Section 4.1.8, Instant Review System, Version 2.0, in force 11 November 2023; and the Instructions to Technical Officials (ITTO), Version 8.0, in force 17 November 2025.
Section 4.1.8 is conditional: IRS must be in operation on that court. It does not require every BWF-rules event, round or court to provide review. Without IRS, Law 17.5 applies the officials' ordinary decisions and overrule procedure; the BWF rules provide no player right to demand review from a broadcast replay, phone recording or other unofficial video. Domestic and local competitions may publish their own conditions, so their prospectus or regulations should be checked.
Reviewable decisions
The challenge is for an in-or-out line call
A player or pair may challenge a line judge's call, an in-or-out call made by the Umpire when no line judge decides it, or the Umpire's overrule of a line judge. If a line judge changes the original decision, or the Umpire overrules it, the Umpire must make the players aware and allow an immediate challenge to the changed call.
Section 4.1.8 is not a general replay system for service faults, net contact, double hits, obstruction, misconduct, the score, or service order. Those matters remain with the responsible official and the ordinary appeal process. See badminton officials and line-judge rules for that division of responsibility.
Timing
“Immediately” has no fixed number of seconds
Section 4.1.8 Regulation 2 requires the challenge immediately after the player observes the call. ITTO 5.8.4 tells the player to say “Challenge” clearly to the Umpire and/or give a clear raised-hand signal.
BWF does not state a five-second, ten-second or other numerical window. The practical test is whether the player challenged at once on observing the call, before the match process moved on. The rule does not create extra time to consult a coach or study a venue replay. If a line judge changes the initial call, or the Umpire overrules it, ITTO 5.8.4 requires the Umpire to make the changed call clear and permit an immediate challenge to that new decision.
Challenge allowance
Two failed challenges end the right for that game
The allowance is not simply “two challenges.” A player or pair may make an unlimited number of challenges until two of them have failed during the game. A failed challenge is one where review confirms that the challenged line call was correct.
The count applies to the player or pair, so doubles partners share it. A successful challenge leaves the right intact. Because the BWF limit is expressed for each game of the match, the failed-challenge count starts again in the next game.
ITTO 5.8.5 changes the spoken announcement in a team tournament—the Umpire names the team rather than the individual challenger—but Section 4.1.8 still states the allowance for the player or pair contesting that game. It does not create one shared challenge pool for an entire team tie.
Successful review
An incorrect original call is reversed
Under Section 4.1.8 Regulation 2, if IRS shows the line judge's or Umpire's original decision was incorrect, the challenge succeeds and that decision is reversed. ITTO 5.8.7 directs the Umpire to announce “Correction, IN” or “Correction, OUT,” followed by the resulting score or service-over announcement.
The rules do not order a replay merely because the original call was wrong: the corrected landing decision supplies the rally result and, under Law 7.3, the rally winner scores the point. If the correction ends the game, ITTO 5.8.7.1 directs the corresponding game announcement.
Unsuccessful review
A confirmed call costs one challenge right
If IRS shows that the original in-or-out call was correct, Section 4.1.8 Regulation 3 makes the challenge a failure and the original result stands. ITTO 5.8.8 directs the Umpire to announce that the challenge was unsuccessful and, where play continues, whether one or no challenges remain before announcing the score and calling play.
The first failed challenge leaves one further failed challenge available in that game. After the second failed challenge, that player or pair cannot challenge another line call until the next game.
No Decision
No Decision does not automatically reverse the call
If IRS returns NO DECISION on a player's challenge to an existing IN or OUT decision, ITTO 5.8.9 says the challenged decision stands. Section 4.1.8 Regulation 3 says neither side loses a challenge right. The system's inability to decide is not a ruling that the official was wrong.
A different result applies when the original report was “unsighted” and the Umpire also could not decide. The Umpire requests IRS under ITTO 5.8.3.3; if IRS then returns No Decision, the Umpire calls a let. Under Laws 14.1 and 14.3, play since the last service does not count and the player who served last serves again.
Umpire review
An Umpire-requested review is not a player challenge
When a line judge is unsighted and the Umpire cannot make the line decision, Section 4.1.8 Regulation 1 and ITTO 5.8.3.3 require the Umpire to ask IRS where it is operating. This is an official request, not a challenge charged to either side.
If IRS returns IN or OUT, the Umpire announces that result and applies it to the rally. If it returns No Decision, the result is a let because there was no underlying IN or OUT decision capable of standing. Without IRS, the Umpire makes the decision if possible; if no decision can be made, Laws 14.2.6 and 17.6.6 require a let.
System problems
A faulty IRS result goes to the Referee
Section 4.1.8 Regulation 3 says a malfunction does not cost either player or pair a challenge right. If the IRS decision is inconsistent—for example, its text conflicts with its graphic—or obviously incorrect, Law 17.5.2 and Section 4.1.8 Regulation 1 require the Umpire to call the Referee; ITTO 5.8.10 says this must happen before the next rally.
The Referee instructs the Umpire how to proceed. The published BWF provisions do not prescribe one automatic outcome for every possible hardware, communication or display failure, so it would be wrong to promise either a let or restoration of the original call in every malfunction. What is fixed is that no challenge right is lost.
Worked case 1
A successful challenge does not spend the allowance
Situation: at 19–19 in the first game, an OUT call against Red is challenged. IRS reports IN.
BWF ruling: the call is corrected to IN and the score is updated for the rally winner. Red has not used a challenge right because Section 4.1.8 Regulation 3 counts failures, not successful requests.
Worked case 2
Doubles partners share the failed-challenge count
Situation: one member of a pair has already made a failed challenge. The partner challenges a later IN call, and IRS confirms IN.
BWF ruling: that is the pair's second failed challenge in the game. Section 4.1.8 uses “player/pair,” so neither partner may make another player challenge until the next game.
Worked case 3
No Decision has two different outcomes
Situation A: a player challenges an existing OUT call and IRS reports No Decision. Ruling: OUT stands and no challenge right is lost.
Situation B: the line judge was unsighted, the Umpire could not decide, and the Umpire requested IRS; IRS reports No Decision. Ruling: let. The decisive fact is whether an original IN or OUT decision existed.
Decision path
Resolve the review in six checks
Is authorised IRS operating on this court? If not, the challenge procedure is unavailable.
Is the disputed decision a line call? Service faults, net contacts, misconduct and scoring disputes are outside Section 4.1.8.
Was the challenge immediate? Look for “Challenge” and/or the clear raised-hand signal as soon as the call was observed.
Does the player or pair still have the right? Two earlier failed challenges in this game end it; successes and No Decisions do not.
What did IRS report? Reverse an incorrect call, retain a confirmed call, or apply the No Decision distinction above.
Is the IRS result inconsistent or obviously incorrect? Call the Referee before the next rally; do not improvise a result.
Common mistakes
Misunderstandings to avoid
“Each player gets two challenges.” In doubles, the pair shares the challenge right.
“You may challenge only twice.” Successful challenges do not reduce the allowance; the right ends only after two failures in a game.
“No Decision means replay the rally.” It produces a let only when the original line decision was unsighted. Otherwise the existing call stands.
“Any officiating call can be reviewed.” BWF Section 4.1.8 covers line calls, not every fault or scoring dispute.
“There is always a set number of seconds to decide.” BWF uses “immediately” and does not publish a numerical challenge clock in Section 4.1.8 or ITTO 5.8.4.
“IRS is available at every BWF-rules match.” The procedure applies only on a court where an authorised system is operating.
“An Umpire review uses one of the player's challenges.” An official request after an unsighted call is not charged to either side.
Checked on 13 August 2026 against the effective BWF documents above and for later amendments affecting this procedure. Section 4.1.8 establishes the BWF baseline but does not guarantee IRS on every court; an event's regulations or prospectus may supplement availability and operating conditions.
Effective rulesets
Version check
This page applies BWF Statutes Section 4.1.8, Instant Review System, Version 2.0 in force 11 November 2023, for review scope, timing, successful and failed challenges, and the two-failure limit. It uses the Laws of Badminton, Version 5.0 in force 26 April 2025—especially Laws 14.2.6, 17.5.2 and 17.6.6—and ITTO Version 8.0 in force 17 November 2025, especially Instructions 2.4–2.5 and 5.8.2–5.8.10, for signals, announcements, unsighted calls, No Decision and faulty IRS results. Whether IRS is available must be checked for the particular competition and court.
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