Badminton — BWF Law 9
A legal serve is a sequence, not just a low contact.
The 1.15-metre height limit receives most of the attention, but a BWF service ruling also checks readiness, delay, court position, feet, release of the shuttle, initial racket contact, continuous forward motion, and the shuttle's flight into the diagonal service court.
Quick ruling: under BWF Laws of Badminton in force 26 April 2025, Version 5.0 (2), the whole shuttle must be below 1.15 metres when the server's racket hits it. That contact alone does not make the serve legal: every other requirement in Law 9.1 must also be satisfied.
Decision path
Check a serve in chronological order
- Confirm the correct server, receiver, and diagonally opposite service courts from the score.
- Check that neither side causes undue delay once ready and that the receiver is ready before delivery.
- From the start of service, watch both players' feet and the service-court boundary lines.
- Watch the server release the shuttle without adding spin.
- At impact, check initial contact with the base and whether the whole shuttle is below 1.15 metres.
- Confirm the racket head continues forwards from the start of service until delivery.
- Follow the shuttle upwards over the net toward the correct service court and decide where it first lands or what it first touches.
Correct players
The score determines the diagonal
Under BWF Laws 10 and 11, the serving side uses its right service court when its score is zero or even and its left court when its score is odd. The correct receiver is the player standing diagonally opposite.
A service-court or service-order error is handled under Law 12: once discovered, it is corrected when the shuttle is not in play and the existing score stands. That administrative correction is separate from judging whether the delivery itself satisfied Law 9.
Readiness
The server cannot quick-serve an unready receiver
Law 9.4 says the server must not serve before the receiver is ready. If the serve is delivered too early, Law 14 provides a let. However, a receiver who attempts to return the service is considered to have been ready.
Readiness does not give either player permission to delay. Once both are ready, Law 9.1 bars undue delay, including delay after the server completes the backward movement of the racket head before starting the service.
Feet and lines
Both feet stay partly grounded and stationary
From the start of service until delivery, Law 9.1.4 requires some part of both the server's and receiver's feet to remain in contact with the court in a stationary position. Lifting, sliding, or dragging a foot during that defined interval can make the service incorrect.
Law 9.1.3 also requires both players to stand within their diagonally opposite service courts without touching the boundary lines. A foot on a service-court line is therefore not rescued by the general rule that a shuttle landing on a relevant line is in.
Start and delivery
The first forward movement starts the service
Once the players are ready, the first forward movement of the server's racket head is the start of service under Law 9.2. Delivery occurs when the racket hits the shuttle or when the server misses it while attempting to serve.
This definition fixes the period during which the stationary-feet and continuous-motion tests apply. A player cannot begin the forward action, stop to unsettle the receiver, and then restart it as a separate delivery.
Release and contact
No added spin, and hit the base first
Law 9.1.5 requires the server to release the shuttle without adding spin and for the racket initially to hit the base. The rule targets the deliberate spin-producing release before impact as well as incorrect initial contact.
The server may use a forehand or backhand action, but the chosen technique must still meet the release, base-contact, height, forward-motion, feet, and flight requirements.
Height
The whole shuttle must be below 1.15 metres
At the instant of racket contact, standard BWF Law 9.1.6 requires the whole shuttle—not merely its cork or the point of contact—to be below 1.15 metres from the court surface.
This fixed-height test replaced informal descriptions based on a player's waist in standard play. Para badminton contains class-specific and alternative service provisions, so those matches must be checked against the applicable clauses rather than the standard 1.15-metre rule alone.
Racket movement
Continue forwards until delivery
Under Law 9.1.7, the movement of the server's racket must continue forwards from the start of service until the service is delivered. The law does not require one particular speed, grip, or swing shape, but it does prohibit a broken forward sequence.
Officials judge the observable racket-head movement together with the undue-delay rule. The issue is the continuity of the delivery, not whether it resembles another player's preferred technique.
Flight and landing
The shuttle travels upwards into the correct court
A correct service must fly upwards from the racket, pass over the net, and—if the receiver does not intercept it—land on or inside the receiver's service court. Singles and doubles use different side and rear service boundaries, so the relevant service-court diagram matters.
If the shuttle touches the net but continues into the correct service court after an otherwise legal delivery, the net touch alone is not a fault or a let under the current BWF Laws. If it fails to cross or lands outside the correct court, the serve is a fault.
No second attempt
Missing the shuttle is a service fault
Law 9.1.8 states that the server must not miss the shuttle when attempting to serve, and Law 9.3 defines that miss as delivery. Because badminton does not provide a tennis-style first and second serve, the fault ends the rally and awards the opponent a point.
A player who has not yet started the service may reset the preparation without attempting delivery, subject to the undue-delay rule. Once the defined forward motion begins, the sequence is judged under Laws 9.2 and 9.3.
Doubles
Partners may position freely without blocking sight
During delivery in doubles, the partners of the server and receiver may take positions anywhere within their respective courts, provided they do not unsight the opposing server or receiver. Only the correct receiver may return the service.
If the receiver's partner hits the served shuttle, Law 13.2.3 makes it a fault. After a legal return, either partner on each side may hit the shuttle in the normal alternating team sequence.
Fault or let
Do not use “let” for every awkward serve
- Fault: the service is incorrect under Law 9.1, the server misses while attempting delivery, or the served shuttle fails to reach the proper court.
- Let: the server serves before the receiver is ready, or both server and receiver are faulted during service.
- Legal play: the shuttle clips the net and lands in the correct service court after a service satisfying every other requirement.
Official references
Source material