Tennis serve rules: faults, lets, foot faults, and service order

Tennis serve rules come down to three things: you get two attempts per point, you hit from behind the baseline, and the ball has to land in the service box diagonally opposite. Miss both attempts and it's a double fault — the receiver wins the point. Everything else follows from those three.

Two serves per point, and the tennis serve rules for a fault

The first serve is the aggressive one because missing it costs only that ball. A fault sends you back for a second serve, which most players slow down and load with spin — miss that one and the point is gone.

A serve is a fault when:

• the ball lands outside the correct service box — in the net, long past the service line, or wide
• you swing at the toss and miss the ball entirely
• the ball hits you, your partner, or anything either of you is wearing or carrying
• the ball hits a net post, singles stick, or permanent fixture before it bounces
• you foot fault

Abandoning a toss is not a fault. As long as you don't swing, you can catch the ball in your hand or on the strings, or let it bounce, and start the motion over. Beyond that the toss rule is loose: release the ball by hand in any direction and hit it before it touches the ground. A player who can use only one arm may use the racket to project the ball.

Two faults on the same point is a double fault, and the point ends there. No rally, no reprieve, and the receiver never has to touch the ball — it's the only way to concede a point without an opponent hitting a shot. Keeping the running count straight through a set of those is why plenty of players hand the arithmetic to a device: Tennis Scoreboard is a tennis scoreboard app for iPhone and Apple Watch that tracks match scores.

Where you stand: the tennis serving rules for foot placement

Before the motion starts, both feet have to be at rest behind the baseline, in the half you're serving from, and inside the imaginary extensions of the center mark and the sideline — the singles sideline in singles, the doubles sideline in doubles. The receiver, by contrast, can stand anywhere on their side of the net: deep behind the baseline, up on the service line, even outside the sidelines. In doubles, so can the receiver's partner.

Foot fault rules, and what actually gets called

There are four ways to commit a foot fault during the service motion:

• changing position by walking or running (slight movements of the feet are fine)
• touching the baseline or the court inside it with either foot
• touching the ground outside the imaginary extension of the sideline
• touching the imaginary extension of the center mark

Jumping is legal. Almost every modern serve leaves the ground and lands well inside the baseline; what matters is that nothing touches down before the racket meets the ball. A foot fault counts as a fault, so one on the second ball is a double fault.

In matches without an official you call your own. The USTA's Code tells players to warn an opponent about a flagrant foot fault first, and to start calling it only if it keeps happening and no official is available.

Deuce court, ad court, and which box to aim at

Every game starts from the right half of your baseline — the deuce court — and the ball goes diagonally into the receiver's right-hand service box. After each point you switch halves: ad court for point two, deuce court for point three, alternating until the game ends. The pattern is even and odd. An even number of points played puts you in the deuce court, which is why 0-0, 15-15, 30-30 and deuce itself all start there, and why every advantage point after deuce is played from the ad court.

A serve that clips any line of the correct box is in — the center service line, the service line, and the sideline all count. If the running count is what trips you up rather than the serve, start with how tennis scoring works.

Lets: when a serve gets replayed

The service is a let when the ball touches the net, strap or band and still lands in the correct box — or touches the net cord and then hits the receiver or their clothing before bouncing. It's also a let if you serve before the receiver is ready, though the receiver is expected to play at your pace, and anyone who attempts a return counts as having been ready.

Two details get missed. A let doesn't erase a fault you've already hit: clip the cord on your second serve and land it in, and you replay the second serve only, not both. And there's no cap — five lets in a row is legal and just means five more attempts.

Not every format plays it that way. US college dual matches have used a no-let rule, in which a serve that catches the cord and lands in stays live. That's a competition variant; under the ITF rules that govern club, junior and professional play, the let stands.

Call	What happened	What it costs
Let	Serve touched the net and landed in the correct box, or the receiver wasn't ready	Nothing — that serve is replayed
Fault	Serve missed the box, was swung at and missed, or broke one of the serving rules	That attempt only
Foot fault	A foot touched the baseline, the court, or the wrong side of an imaginary line during the motion	Counts as a fault
Double fault	Two faults on the same point	The point, immediately

Who serves first in tennis, and how service changes hands

A racket spin or coin toss before the warm-up decides it. The winner takes one of three choices: serve or receive first, pick an end, or make the opponent choose first — and whatever the winner leaves, the opponent takes. After that it alternates, with the server becoming the receiver at the end of every game.

Service order carries across sets rather than resetting. Whoever received the last game of a set serves the first game of the next one. In doubles, each team fixes its serving order at the start of every set and keeps it for that set; you can reorder between sets, never mid-set.

Serving in a tiebreak

The player whose turn it is serves the first point, from the deuce court. Service then passes every two points, and each new server begins from the ad court. Ends change every six points, and whoever served the tiebreak's opening point receives first in the following set. The rest of the sequence is in tiebreak rules.

Is an underarm serve legal?

Yes, at every level, Grand Slams included. The rules require only that you release the ball by hand and strike it before it hits the ground — nothing specifies an overhead motion. Objections to it are about etiquette, not legality. What you can't do is let the toss bounce and then play it off the ground.

FAQ

What is a let in tennis?

A serve that touches the net, strap or band and still lands in the correct service box. It's replayed at no cost, and it doesn't cancel a fault you've already hit — a let on the second ball means you serve a second serve again. Serving before the receiver is ready is also a let.

Do you lose the point on a double fault?

Yes. Two faults on the same point ends it immediately, and the receiver takes the point without touching the ball. A foot fault on the second serve counts the same way, since a foot fault is simply a fault.

Is it a foot fault if you touch the baseline?

Yes. Touching the baseline during the service motion is a foot fault, exactly like stepping inside the court. Landing inside after you've struck the ball is fine, which is why jumping serves are legal.

Can you serve underarm?

You can. No rule requires an overhead serve — only that you release the ball by hand and hit it before it bounces. It's legal in sanctioned and professional play.

Who serves first in a new set?

Whoever received the last game of the previous set; service keeps alternating across the set boundary. If the set ended in a tiebreak, the player who served the tiebreak's first point receives first in the new set.