What Happens If You Serve From the Wrong Side in Tennis? Points Stand, Switch Now

There is one catch. If you had already missed a first serve from the wrong half before the mistake was spotted, that fault still counts. Your next serve is a second serve, and Rule 20 says you hit it from the correct half rather than the one you just faulted from.

The rule in one line

Rule 27 opens with the principle that settles almost every argument: when an error is discovered, "all points previously played shall stand." The lettered parts of the rule then say how to fix each kind of mistake from that moment on. Nobody loses a point for having served from the wrong half, and nobody gets a point back either.

Every serving mix-up, and how it is fixed

The wrong side is only one of several mistakes Rule 27 covers. They are easy to confuse, and the fault rules are different for each.

Mistake	What you do	Does an earlier fault count?	Rule
Server on the wrong half (deuce or ad)	Switch to the correct half for the score right away	Yes, it stands	27a
Players at the wrong ends of the court	Change to the correct ends right away	No, it does not stand	27b
Wrong player serving, caught mid-game	The player originally due to serve takes over	No, if the opponent served it. Yes, if it was the server's own doubles partner	27c
Wrong player served a whole game	Leave it. The serving order stays as it now is	Not relevant	27c
Wrong player serving in a tie-break	Correct it if an even number of points have been played; after an odd number, the order stays	Same as 27c	27d
Doubles receivers on the wrong sides	Keep the swapped order to the end of the game, then go back to the original order	Points stand	27e

When the wrong player serves a whole game and the order stays altered, Rule 27c adds a small housekeeping step: any ball change due after a set number of games moves one game later than planned.

Working out the correct side from the score

Rule 17 says the server starts every standard game from behind the right half of the court and alternates halves after each point. That gives a simple check you can do from the score alone: add up the points played in the game.

Points played in the game	Example scores	Serve from
Even	0-0, 15-15, 30-0, 0-30, 40-15, deuce	Right half (deuce court)
Odd	15-0, 0-15, 30-15, 40-30, advantage	Left half (ad court)

Tie-breaks work the same way. Rule 17 says the first point of a tie-break is served from the right half, and serves then come from alternate halves. If you are not sure who should be serving in the tie-break at all, our guide to how a tennis tiebreak works walks through the order point by point.

Two worked examples

Served from the ad side at 30-15. Three points have been played, an odd number, so you should be on the left (ad) half. Say you served the 30-15 point from the right half instead, missed your first serve, and your opponent then pointed it out. Rule 27a applies: the fault stands, so you are on your second serve, and you hit it from the left half. The earlier points in the game do not change.

Wrong ends, found after a first-serve fault. Here Rule 27b applies instead, and its last sentence is the opposite of 27a: a fault served before the error was discovered "shall not stand." You change ends and start the point again with a first serve. USTA's What's the Call page on serving from the wrong end covers a singles match where the players forgot to change ends and noticed in the middle of the fourth game. The answer: correct it immediately, even if one player would rather finish the game first.

Doubles: the receivers are on the wrong sides

In doubles, the receiving team picks who receives the first point of their first receiving game in each set, and then the partners alternate. If they get that rotation wrong partway through a game, Rule 27e says the altered order stays until the end of that game. The next time they receive in that set, they go back to their original order. USTA answered this exact case in Serving to the wrong side, where a team noticed after a long rally that they had received from the wrong sides. The altered order stays to the end of the game, and the team returns to its original order the next time it receives. Under the Rule 27 principle, the rally they just played stands.

Is a serve from the wrong half a fault?

Rule 19a lists breaking Rule 17, the rule that sets out alternate halves, among the causes of a service fault. Rule 27a is the part that deals with an error discovered later: points already played stand, a fault served before the discovery stands, and the server moves to the correct half. Neither rule lets a player claim back a point that has already finished. If you notice the server is on the wrong half before the serve, say so then, when fixing it costs nobody anything.

Stopping the mistake before it happens

In matches without an official, the USTA Code (item 31 in the 2026 Friend at Court) says the server must announce the game score before the first point of a game and the point score before every point after that. Saying the score out loud is the easiest way to catch a wrong side, because the score tells you the side.

If the players cannot agree on the score, or on which court a disputed point started from, Code item 32 lists the ways to settle it in order of preference:

1. Count all the points and games the players agree on and replay only the disputed ones. If you do not agree on which court the disputed point started in, toss a coin to choose the court.
2. Play from a score that all players agree to.
3. Spin a racket or toss a coin.

Keeping score on a phone with our tennis score keeper helps too: if the score is right, the side is right. If your mix-up was about who serves in the first place rather than where, see who serves first in tennis.