What Is a Double Fault in Tennis? The Rule and a Simple Fix

A double fault happens when the server commits a fault on both serve attempts for the same point. The receiver wins the point. A first-serve fault alone does not change the score because the server still has a second serve; if that second attempt is also a fault, the point is over. The USTA summarizes the sequence: players receive two chances to put the serve in play, and the opponent wins the point after a missed second serve.

For example, at 30–15:

1. Your first serve lands beyond the correct service box: first fault.
2. Your second serve hits the net and does not cross: double fault.
3. You lose that point, making the score 30–30.

You do not lose two points. “Double” describes the two faults, not the scoring penalty.

What counts as a serve fault?

A serve must travel diagonally into the correct service box. A fault can occur when you:

• hit the serve into the net;
• land the ball outside the correct service box;
• serve from the wrong position or into the wrong box;
• touch the baseline or court with a foot during the service motion; or
• swing at the tossed ball and miss it.

The ITF Rules of Tennis define foot faults and list breaking the service, serving or foot-fault rules among the causes of a service fault. A serve touching a boundary line of the correct service box is good because a ball touching a line counts as touching the court enclosed by that line.

A serve that clips the net and then lands in the correct box is different: it is a let, and that serve is replayed. If it clips the net and lands outside the correct box, it is a fault, as the USTA’s serving guide explains.

After a first fault, serve again from the same side of the baseline. The ITF second-service rule specifies the same half of the court, unless the original serve came from the wrong half.

How to reduce double faults

Treat the second serve as a separate shot with a simple job: clear the net and reach a large target. Do not merely repeat an unreliable first serve and hope for a different result.

Try this two-serve drill:

1. Place a large target in the middle of the correct service box.
2. Play 10 simulated points, taking a first and second serve when needed.
3. Use your normal first serve.
4. On the second serve, keep a complete, comfortable motion but aim higher over the net and toward the large target.
5. Record double-faulted points, not just total serves made.

Your readiness checkpoint is straightforward: complete 10 simulated points with no more than one double fault, twice. Then make the target slightly smaller or alternate between the deuce and ad courts.

If the ball still misses in several different ways, resist rebuilding the entire motion at once. Fix one serve change at a time, then use the same two-serve test again. For a fuller progression from toss and contact checks to placement, use these tennis serve drills.