What Is a Fault in Tennis? Rules, Examples and Double Faults

A fault in tennis is an unsuccessful serve. The server breaks a serving rule or fails to land the ball in the correct service box, but a single fault does not immediately cost the point. The server is normally allowed one more serve.

If the second serve also fails, it is called a double fault. A double fault awards the point to the receiver. This is why understanding the difference between a fault, a let and a double fault matters when following a tennis match.

What counts as a fault on a tennis serve?

A serve is a fault when the ball does not meet the rules for a legal delivery. Common examples include:

• Missing the correct service box: The served ball lands outside the diagonally opposite service court, including on the wrong side of the center line.
• Hitting the ball outside the service box: A serve that lands beyond the service line or outside the singles or doubles sideline is a fault.
• Touching the net or another permanent fixture: If the serve hits the net and then lands outside the correct service box, it is a fault. A ball that hits the net and lands in the correct box is generally a let, so the serve is replayed.
• Serving from the wrong position: The server must serve from behind the baseline and from the correct side of the court based on the score.
• Foot fault: The server commits a foot fault by touching the baseline, the court inside it, the wrong side of the center mark or the area outside the sideline before making contact with the ball.
• Failing to hit the tossed ball: The server must make a legal serving motion and strike the ball. Deliberately catching or missing the toss can be ruled a fault, depending on the circumstances and the official’s judgment.

The serve must also be delivered after the receiver is ready and without an unreasonable delay. A server who violates the time or serving procedure rules may receive a fault under the applicable competition regulations.

What happens after a fault?

After a first serve fault, the point continues with a second serve. The server starts the second attempt from the same end of the court and must serve into the correct diagonal service box.

If the second serve is also unsuccessful, the server commits a double fault. The receiver wins the point without having to return the ball. The score then changes as it would after any other lost point.

For example, if a player misses the first serve into the net and then sends the second serve beyond the service line, the second error is a double fault. The opponent receives the point.

Fault versus let in tennis

A fault ends that serving attempt and counts as one of the server’s two chances. A let does not count as a fault; the serve is replayed.

The most familiar example is a serve that clips the net and still lands in the correct service box. The umpire calls a service let, and the server repeats that serve. If the ball hits the net and lands outside the correct box, the result is a fault instead.

A let can also be called when play is interrupted by an outside event or when the receiver was not ready and did not attempt to return the serve. The exact decision can depend on the rules and the official’s judgment.

What is a foot fault?

A foot fault in tennis happens when the server’s feet touch a restricted boundary or area during the serving motion before the racket strikes the ball. The server must remain behind the baseline, between the center mark and the relevant sideline.

A foot fault is treated as a serving fault, even if the ball lands perfectly in the service box. The umpire may call it when a player steps on the baseline, crosses the center mark or moves outside the permitted side boundary.

Does a fault lose the point?

A first fault does not lose the point. It uses one of the server’s two attempts and leads to a second serve. A second consecutive fault does lose the point because it becomes a double fault.

That rule applies in singles and doubles. In doubles, the serving team rotates through its service order, but each individual service turn still allows a first serve and a second serve.

How faults appear in tennis scores and statistics

During a match, officials may announce a fault without changing the game score. Match statistics usually record first-serve percentage, second serves and double faults. A high number of double faults can give the receiver free points, while frequent first-serve faults force the server to rely on a more cautious second serve.

Not every missed shot is a fault. A player who misses a groundstroke during a rally has made an unforced error or a forced error, depending on the circumstances. In standard tennis terminology, “fault” most commonly refers to an illegal or unsuccessful serve.