ScopeThe rule and version used here
This page applies the 2026 ITF Rules of Tennis published by World Tennis, whose rulebook still uses the name International Tennis Federation (ITF). Rules 21 and 22 control readiness and the service let; Rules 20 and 29 control second-service pace and continuous play.
The page was checked on 28 August 2026 against the ITF's published 2026 amendments. Those amendments change other subjects, not Rules 20–22 or 29. ATP and USTA provisions below are labelled because their enforcement procedures do not apply universally. A tournament's own regulations and code of conduct may supplement the ITF baseline.
Two duties“Ready” and “reasonable pace” operate together
ITF Rule 21 creates two simultaneous duties:
- Server: do not serve until the receiver is ready.
- Receiver: play to the server's reasonable pace and become ready within a reasonable time after the server is ready.
Neither player has complete control of the interval. “Reasonable” leaves a factual judgment for the official: the receiver cannot demand a private reset before every point, and the server cannot turn pace into an ambush.
Readiness testAn attempted return settles the issue
Rule 21 supplies one conclusive test: a receiver who attempts to return the service is considered ready. A swing, block or other genuine attempt therefore prevents the receiver from waiting to see the outcome and then claiming unreadiness.
If there is no attempt, unreadiness is not automatic. It still has to be demonstrated from the circumstances. The ITF rule does not prescribe a particular receiving stance, eye direction, raised-hand signal or number of seconds that by itself proves readiness. Those details can be evidence, but the rule's express test is the attempted return.
Exact outcomeAn unready-receiver serve is a service let
ITF Rule 22(b) makes the result mandatory when unreadiness is established: the service is a let. That particular service does not count and the server serves again.
- On first service: repeat the first service.
- After a first-service fault: repeat the second service; the earlier fault remains.
- If the rushed ball lands out: Rule 21 says it cannot be called a fault once unreadiness is demonstrated. Apply the service let instead.
- If the receiver attempts a return: the receiver is deemed ready, so the ordinary result of the serve and rally stands.
This is narrower than replaying everything that happened earlier in the point sequence: Rule 22 expressly says a service let does not cancel a previous fault.
Quick servesSpeed alone does not decide legality
A prompt serve is legal when the receiver is ready. It becomes a Rule 22 service let when the receiver is not ready and that unreadiness is demonstrated. The Rules of Tennis do not create a separate offence named “quick serve,” so the useful questions are readiness, attempted return and—separately—whether either player delayed the reasonable pace.
Do not play both options: under the ITF rule, trying the return means readiness. A receiver who is genuinely unready should make no attempt and raise the issue immediately under the applicable officiating procedure.
25-second limitThe clock is a ceiling, not the receiver's personal allowance
ITF Rule 29 allows a maximum of 25 seconds from the end of one point until the first service is struck for the next point. It also allows 90 seconds on ordinary changeovers and 120 seconds at set breaks; after the first game of a set and during a tie-break, players change ends without a rest.
The 25 seconds do not give the receiver a right to use the whole period when the server is ready earlier and proceeding at a reasonable pace. Equally, the clock does not cancel Rule 21: the server still must not serve an unready receiver. Readiness and delay are separate decisions with separate consequences.
Delay enforcementPenalise delay; do not convert it into a playable quick serve
The 2026 ITF Duties and Procedures for Officials says a receiver may receive a Time Violation before 25 seconds have expired when the receiver's actions delay the server's reasonable pace. Consistent or obvious delay used as gamesmanship may instead be treated as Unsportsmanlike Conduct under the applicable event code.
That procedure addresses the receiver's delay. It does not amend Rules 21 and 22 or make a serve at an unready receiver count. The official should deal with the delay under the competition's code and deal with any serve actually struck at an unready receiver as a service let.
ATP variationATP 2026 specifies the escalating penalty
For ATP Tour and ATP Challenger Tour matches, the 2026 ATP Official Rulebook, Chapter VIII, Continuous Play uses the same 25-second maximum and permits a receiver Time Violation before the clock expires when the receiver is holding up the server's reasonable pace.
The first time violation is a warning. On a later time violation, a serving player is penalised with a fault, while a receiving player receives a one-point penalty. A prior warning follows the player across roles: a warning received while serving makes a later receiver delay the player's second time violation. Consistent or obvious receiver delay may be handled as Unsportsmanlike Conduct. The ATP's 27 April 2026 published update did not amend this provision.
Second service“Serve again” does not always mean two serves
ITF Rule 20 requires a second service after a first-service fault to be struck without delay. If that second serve is delivered while the receiver is unready, Rule 22 repeats only that second service because the previous fault survives.
Do not confuse that ruling with a separate interruption before the second serve. For example, USTA Friend at Court 2026, The Code §30, says that in U.S. play a delay between serves gives the server one serve if the server caused it, but two serves if the receiver caused it or outside interference caused it. A brief ball-clearance delay is not enough unless it becomes so prolonged that it constitutes an interruption. That USTA guidance is a national procedure, not additional wording in ITF Rule 22.
U.S. unofficiated playUSTA's Code adds practical call guidance
For matches in the United States governed by USTA Friend at Court 2026, The Code §29 says an attempted return—even of a “quick” serve—presumes the receiver or receiving team was ready. It also says a receiver who is ready may not become unready unless outside interference occurs.
In matches where players retain the calling responsibilities, The Code §27 allows any player to call a service let, but requires the call before the return goes out of play or is hit by the server or server's partner; an apparent or near ace requires a prompt call. An appointed official may assume responsibilities that players otherwise perform, so players should follow that event's officiating instructions.
Decision pathHow to rule a disputed serve
- Identify the ruleset. Start with ITF 2026, then check the event's regulations and code.
- Ask whether the receiver attempted a return. If yes, Rule 21 treats the receiver as ready and the point is ruled normally.
- If there was no attempt, decide whether unreadiness is demonstrated. No attempt alone is not the complete test.
- If unready, call a service let. Disregard that service under Rule 22.
- Preserve any previous fault. A let on second service means another second service.
- Assess delay separately. If the receiver or server caused unreasonable delay, apply the appointed competition's time- or conduct-violation procedure.
Worked case 1A rushed first serve lands out
Situation: the receiver is still retrieving position, makes no attempt, and the server's first serve lands beyond the service line.
ITF 2026 ruling: if the official is satisfied that the receiver was not ready, call a service let and repeat the first service. Rule 21 says the serve cannot be called a fault when unreadiness is demonstrated; where the ball landed does not change that.
Worked case 2The receiver reflexes a return into the net
Situation: the serve arrives sooner than expected. The receiver blocks at it, and the return hits the net and fails to cross.
ITF 2026 ruling: the receiver is deemed ready because there was an attempt to return. The receiver loses the point under the ordinary rules; “I was rushed” cannot be used after trying the shot.
Worked case 3A quick second serve follows a fault
Situation: after a first-service fault, the server hits the second serve while the receiver is demonstrably unready. The receiver makes no attempt.
ITF 2026 ruling: service let; repeat the second service. Rule 22 says the let does not cancel the previous fault, so the server does not regain a first service.
Worked case 4The receiver towels while the server waits
Situation: at an ATP event, the receiver repeatedly goes to the towel although the server is ready and the chair umpire judges the server's pace reasonable. Only 15 seconds have elapsed.
ATP 2026 ruling: the chair may issue a Time Violation before 25 seconds. The first is a warning; a later receiver time violation is a point penalty. The receiver cannot insist that the remaining ten seconds belong to the receiver.
Worked case 5A stray ball interrupts the second-serve sequence
Situation: in a USTA match, outside interference causes a prolonged delay after a first-service fault but before the second service is struck.
USTA 2026 ruling: The Code §30 gives the server two serves when outside interference causes the delay. This is an interruption ruling under USTA guidance, not an unready-receiver service let; a short routine clearance is not automatically prolonged enough.
Common mistakesFive claims the rules do not support
- “A quick serve is always a fault.” There is no quick-serve fault; the relevant result is a service let if unreadiness is demonstrated.
- “No swing always means a let.” No attempt avoids being deemed ready, but unreadiness must still be demonstrated.
- “A raised hand automatically stops the server.” ITF Rule 21 prescribes no universal hand-signal veto.
- “The receiver owns all 25 seconds.” The receiver must follow the server's reasonable pace and may be penalised earlier under the applicable procedure.
- “Any let after a first fault restores first service.” An unready-receiver service let preserves the fault; a separate whole-point interruption or competition-specific delay rule may produce a different result.
Official referencesGoverning-body sources and effective versions
Checked on 28 August 2026 against the ITF 2026 rulebook and amendment notice. ITF Rules 21 and 22 are the baseline ruling. ATP 2026 is cited only for ATP penalty escalation, and USTA Friend at Court 2026 only for U.S. call and interruption procedures. Grand Slam, WTA, collegiate, national-association and individual tournament regulations may add different enforcement procedures and should be checked for those competitions.