A legal serve must pass every Law 9 test.

The ruleset used on this page

The baseline here is BWF Statutes Section 4.1, Laws of Badminton, Version 5.0 (2), in force from 26 April 2025 and current when this page was checked on 13 August 2026. The main provisions are Laws 9–14 and 17.

This is the international BWF rules family, not a promise that every school, club, age-grade league or domestic tournament uses the same service-height test. A competition may specify the BWF Alternative Service Laws, and Para badminton uses the class-specific clauses printed in Section 4.1. Check the event prospectus or regulations before treating a variation as controlling.

Check the serve in this order

1. Identify the ruleset. Standard BWF, Alternative Service Laws and Para badminton do not share one universal height test.
2. Identify the players and courts. Confirm the correct server, receiver and diagonal service courts from the score and service order.
3. Check readiness and delay. The receiver must be ready, and neither side may cause undue delay once both are ready.
4. Mark the start. Once both players are ready, the first forward movement of the server's racket head starts the service.
5. Watch position and feet. Apply Laws 9.1.3 and 9.1.4 until delivery.
6. Watch release and impact. Check added spin, initial contact with the base and the applicable height test.
7. Follow the action and flight. The racket must continue forwards, and the shuttle must travel upwards over the net towards the correct service court.
8. Choose the result. Distinguish a fault, a let, a service-court error and a legal net-cord serve.

The serving side's score selects right or left

Under BWF Laws 10.1 and 11.1, the serving side serves from the right service court when it has not scored or has an even score in that game, and from the left when its score is odd. In doubles, the receiver is the player in the diagonally opposite service court.

Singles uses the inner side line and back boundary line for the service court. Doubles uses the outer side line and the doubles long service line. The short service line is the front boundary in both. Under Law 1.3, each boundary line forms part of the area it defines, so a served shuttle landing on the relevant line is in.

A service-court error is corrected, not replayed

Serving or receiving out of turn, or from the wrong service court, is a service-court error under Law 12. When it is discovered, the players correct the error while the shuttle is not in play and the existing score stands.

That is different from an illegal delivery under Law 9. A completed rally is not erased merely because the players later notice that the wrong player served or received.

The server may not serve before the receiver is ready

Law 9.4 prohibits serving before the receiver is ready. If the server does so, Law 14.2.1 makes the result a let: the rally does not count and the same server serves again. A receiver who attempts to return the service is treated as having been ready.

Readiness is not a licence to stall. Law 9.1.1 bars either side from causing undue delay once both are ready, and Law 9.1.2 treats delay after the server completes the racket head's backward movement as undue delay. The BWF Instructions to Technical Officials also tell the receiver not to delay getting ready once the server is in position and ready.

The first forward racket-head movement starts the service

Once the players are ready, Law 9.2 defines the first forward movement of the server's racket head as the start. Under Law 9.3, delivery occurs when the racket hits the shuttle or when the server misses the shuttle while attempting to serve.

These two moments fix the interval for the stationary-foot and continuous-forward-motion tests. Before the defined start, a player may reset the preparation, subject to the undue-delay rules. After it starts, stopping and beginning another forward action does not create a fresh attempt.

Some part of each foot must stay grounded and stationary

Law 9.1.3 requires the server and receiver to stand inside diagonally opposite service courts without touching their boundary lines. A foot on a service-court line is therefore illegal even though a shuttle landing on the relevant line is in.

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. The law does not require both feet to be flat, but it does require a stationary point of contact for each foot throughout that interval.

Do not add spin on release; hit the base first

BWF Law 9.1.5 has two separate tests: the server must release the shuttle without adding spin, and the racket must initially hit the shuttle's base. The first part prohibits a spin-producing release before impact; the second identifies which part the racket must contact first.

Do not enlarge that wording into a ban on every shuttle rotation after a legal racket strike. The rule controls the release and the initial point of racket contact. A forehand, backhand, low serve, flick serve or drive serve can be legal if it satisfies every Law 9 requirement.

The entire shuttle must be below 1.15 metres

For standard BWF play, Law 9.1.6 judges height at the instant the racket hits the shuttle. Every part of the shuttle—not only the cork, the racket contact point or the server's hand—must be below 1.15 metres from the court surface.

The rule says “below”, so contact with any part of the shuttle at or above that height fails the test. Player height and anatomy do not change the fixed measurement.

Some competitions use waist height and a downward racket

BWF Statutes Section 4.1.4, Alternative Service Laws Version 1.0, replaces standard Law 9.1.6 with two tests:

• The whole shuttle must be below the server's waist at impact; “waist” is the imaginary line around the body level with the lowest part of the bottom rib.
• The racket shaft and racket head must point downwards at impact.

All other Laws of Badminton continue to apply. This alternative is not automatically triggered because a hall has no service-height measuring device. Apply it only when the competition's appointed rules say that it governs the match.

Class-specific service provisions replace parts of the baseline

The Para clauses within BWF Section 4.1 and the BWF Para technical-official instructions make the important distinctions:

• Wheelchair badminton: the whole shuttle must be below the server's armpit at impact, with the racket pointing downwards. The wheels of server and receiver remain stationary from start to delivery, except for the server's natural wheelchair counter-movement.
• Standing classes: the alternative waist-height and downward-racket tests apply. Some classes use the half-court diagram specified by the Laws.
• Medical exception: Law 9.1.4.2 permits medically justified exceptions to the standard foot requirement for players identified by the Head of Classification; the Referee and Technical Delegate use that list.

These are express BWF provisions, not discretionary relaxations that players or a local umpire may invent during a match.

The racket must continue forwards until delivery

Under Law 9.1.7, movement of the server's racket must continue forwards from the start of service until delivery. A pause or reversal after the first forward racket-head movement breaks the required sequence.

The standard law does not prescribe a grip, swing speed or racket-head angle at impact. The downward-racket requirement belongs to the Alternative Service Laws and the stated Para provisions, not the standard 1.15-metre test.

The shuttle must travel upwards towards the proper court

The opening words of Law 9.1 require an upward flight from the server's racket, over the net, so that an unintercepted serve would land on or inside the receiver's service court. Hitting hard, serving flat or using a flick is not a named fault by itself; the observed flight and the other Law 9 tests decide legality.

If the receiver intercepts a correct serve, it need not first land in the service court. If it is not intercepted, the relevant singles or doubles boundary determines in or out.

Touching the net does not automatically create a let

An otherwise correct serve that clips the net, crosses it and lands in the proper service court remains in play. BWF has no tennis-style service let merely for a net touch.

There is a fault if the served shuttle is caught on top of the net, is caught in the net after passing over it, fails to pass over, or lands outside the correct service court. The separate Law 14 let for a shuttle caught on or in the net applies only after the service has been returned (with the stated wheelchair exceptions).

Missing after the service starts is a fault

Law 9.1.8 says the server must not miss the shuttle when attempting to serve, and Law 9.3 treats that miss as delivery. The incorrect service is a fault under Law 13.1; there is no second serve.

By contrast, dropping the shuttle before the defined first forward racket-head movement is not the “miss” described by Law 9.3. The server can prepare again unless the conduct creates undue delay.

Partners may stand freely, but may not block sight

During delivery, Law 9.5 allows the partners of server and receiver to stand anywhere within their respective courts provided they do not unsight the opposing server or receiver. The partner need not stay inside a service court.

Only the designated receiver may return the serve. If the receiver's partner hits it, Law 13.2.3 makes that a receiving-side fault. Once the service has been returned, either partner may take the next stroke for that side.

Service mechanics are factual calls, not IRS challenges

Under Law 17.3 and BWF ITTO 7.2, an appointed service judge judges the server's compliance with Laws 9.1.2–9.1.8 and calls “Fault” with the appropriate signal. The umpire watches the receiver and may also call a service fault; where an official is absent, the umpire arranges for that duty to be carried out.

An official's decision is final on the points of fact assigned to that official. The Instant Review System decides line-call challenges, not replay challenges to service height, foot position, spin or racket motion. A dispute about application of the law must be raised before the next service; only an unsatisfied appeal on a question of law is referred to the Referee under Law 17.6.8.

Fault, let and correction have different consequences

• Server faults: the receiving side wins the rally and scores a point under Law 7.3; it then becomes the serving side under Laws 10.3.2 or 11.3.2.
• Receiver faults: the serving side wins the rally and scores; the same server serves again from the alternate service court under Laws 10.3.1 or 11.3.1.
• Both server and receiver are faulted during service: Law 14.2.2 requires a let. No point is scored and the last server serves again.
• Serve delivered before receiver is ready: it is a let under Law 14.2.1, unless the receiver attempted a return and was therefore deemed ready.
• Wrong court or order discovered: correct the Law 12 error when the shuttle is not in play; the score already reached stands.

A hard flick serve passes the receiver

Situation: in an ordinary BWF doubles match, the server contacts the entire shuttle below 1.15 metres, uses a continuous forward action and sends it sharply upwards over the receiver. It lands on the doubles long service line.

BWF Version 5.0 (2) ruling: legal serve, assuming every other Law 9 test is met. Speed and the flick technique are not faults, and the doubles long service line forms part of the service court.

The server's toe touches a boundary line

Situation: the shuttle contact and flight are legal, but the server's shoe touches the centre line when the service starts.

BWF Version 5.0 (2) ruling: service fault under Laws 9.1.3 and 13.1. A line counts as in for a landing shuttle but may not be touched by the server or receiver while standing in the service court.

The shuttle clips the tape and drops in

Situation: an otherwise correct serve touches the top tape, crosses the net and lands on the short service line in the correct diagonal court.

BWF Version 5.0 (2) ruling: play continues. The line is in, and a net touch alone is neither a fault nor a let. The answer changes if the served shuttle remains caught on top or in the net.

The receiver steps as the forward swing begins

Situation: both players are ready. At the server's first forward racket-head movement, the receiver lifts one foot completely and then returns the serve.

BWF Version 5.0 (2) ruling: receiving-side fault under Law 9.1.4. Attempting the return confirms readiness under Law 9.4; it does not cure the foot fault. If the server is also faulted during that service, Law 14.2.2 instead makes it a let.

A club has no 1.15-metre measuring device

Situation: players assume that the old waist test automatically replaces the fixed-height rule because no service judge or measuring device is present.

BWF ruling: absence of equipment does not itself rewrite Law 9.1.6. Standard BWF play still uses 1.15 metres. If the competition has expressly appointed Alternative Service Laws Version 1.0, use its waist-height and downward-racket tests instead. The decisive fact is the appointed ruleset, not the equipment available.

Five claims to correct

• “Contact below the waist is always the rule.” Standard BWF Law 9.1.6 uses a fixed 1.15-metre height; waist height belongs to the alternative and stated Para provisions.
• “The racket head must point down in every match.” Not under the standard fixed-height law. It is required by the Alternative Service Laws and the relevant Para rules.
• “Both feet must be flat.” Law 9.1.4 requires some part of each foot to remain grounded and stationary.
• “A net-cord serve is replayed.” It remains live if otherwise correct and it crosses into the proper service court.
• “A wrong server means the rally is replayed.” Law 12 says to correct the service-court error and keep the existing score.

Governing-body sources and effective versions

• Badminton World Federation — Statutes Section 4.1, Laws of Badminton, in force 26 April 2025, Version 5.0 (2): Laws 1, 7 and 9–17
• Badminton World Federation — Statutes Section 4.1.4, Alternative Laws of Badminton, Version 1.0: Alternative Service Law 9.1.6
• Badminton World Federation — Statutes Section 4.1.1, Instructions to Technical Officials, in force 17 November 2025, Version 8.0: Instructions 2.4, 5.4.3, 5.4.8, 6.8 and 7.2–7.4 (BWF document copy hosted by Badminton Denmark)
• Badminton World Federation — Statutes Section 4.1.1.1, Instructions to Para Badminton Technical Officials, in force 8 November 2025, Version 6.0 (1): Instructions 8.2–8.4 (BWF document copy hosted by Ghana Badminton)

Checked on 13 August 2026 against the BWF law book, its published Alternative Service Laws and the current BWF instructions for technical officials. Standard rulings on this page use Section 4.1 Version 5.0 (2). Competition prospectuses, domestic regulations and Para classifications may specify the published alternatives or additional procedures; where they do, those appointed provisions control that match.