Table Tennis Serve Rules: What Makes a Serve Legal
TL;DR
A legal table tennis serve starts with the ball resting on your open, still palm, above the table and behind your end line. You must throw it near-vertically at least 16cm without spin, then strike it as it falls so it bounces once on your side and once on theirs. The ball must stay visible to your opponent the whole time. In singles there is no requirement to serve diagonally — that rule applies only to doubles.
On this page9
The five things a legal serve must do
The ITTF spells the service out in five short clauses. Every legal serve satisfies all of them, and almost every illegal serve you will see breaks one of the last two.
| # | Law | Requirement |
|---|---|---|
| 1 | 2.6.1 | The ball rests freely on the open palm of your stationary free hand |
| 2 | 2.6.2 | You throw it near vertically upwards, without spin, so it rises at least 16cm and falls untouched |
| 3 | 2.6.3 | As it falls, you strike it so it touches your court first, then the receiver’s |
| 4 | 2.6.4 | From start until struck, the ball stays above the playing surface, behind your end line, and not hidden from the receiver |
| 5 | 2.6.5 | Once thrown, your free arm and hand leave the space between the ball and the net |
The open palm, and why it matters
Law 2.6.1 is more specific than most players realise. The ball must rest freely on an open palm, and the free hand must be stationary. Cupping the ball, gripping it with fingers, or lifting it from a moving hand are all illegal — not because officials are being fussy, but because each of them lets you impart hidden spin at the moment of release.
The same logic runs through 2.6.2: the throw must be near vertical and without spin. A serve tossed backwards over your shoulder or angled into your body is not legal even if everything else looks right. Every rule on this page comes from the ITTF’s own statutes rather than a coaching site — our research and sourcing policy explains why that distinction matters for rules content.
The 16cm toss
The ball must rise at least 16cm after leaving your palm. There is a neat way to remember it: the net is 15.25cm high, so a legal toss clears the height of the net by a fraction.
Two details people miss. First, 16cm is a minimum, not a target — throwing it two metres up is perfectly legal, and some players do exactly that. Second, the ball must fall without touching anything before you strike it, and you must hit it as it is falling, never on the way up.
The hidden serve rule
This is the modern game’s most consequential service law, and the one most often broken at club level.
Under 2.6.4, from the start of the service until the ball is struck, it must not be hidden from the receiver — not by the server, not by a doubles partner, and not by anything they wear or carry. 2.6.5 goes further: as soon as the ball has been thrown, the free arm and hand must be removed from the space between the ball and the net, which the law defines as the region bounded by the ball, the net, and the net’s indefinite upward extension.
Together these exist for one reason: your opponent must be able to see the racket strike the ball, so they can read the spin. Serving from behind your body or leaving your arm across the ball hides the contact, and that is precisely what the law forbids.
You do not have to serve diagonally in singles
This is the most widespread myth in the sport, and the law is unambiguous.
Law 2.6.3 requires the ball to touch your court and then “directly the receiver’s court”. The diagonal requirement — right half court to right half court — appears only in the clause that begins “in doubles”.
So in singles, you may serve anywhere on your opponent’s side of the table. Down the line, into the middle, wide to the backhand: all legal. The half-way line painted on the table is there for doubles and has no meaning in a singles game.
Misconceptions like this survive because people learn a sport by watching rather than by reading its law book. Rugby’s offside rule is misunderstood for the same reason.
What happens when a serve is illegal
Other sports police technique just as strictly at the moment a race or rally begins — swimming’s start and stroke rules disqualify on form rather than on speed, and can do so after the race has already been swum.
An incorrect service simply gives your opponent a point (Law 2.10.1.1). But the law includes a sensible piece of humanity for borderline cases.
Under 2.6.6, it is the player’s responsibility to serve so that the umpire can be satisfied it is legal — the burden of proof sits with the server, not the official. And under 2.6.6.1, if the umpire is genuinely unsure about a service’s legality, they may, on the first occasion in a match, interrupt play and warn the server without penalty. After that, any serve from that player or their doubles partner that is not clearly legal is judged incorrect.
One warning, then points. It is a deliberate design: doubt goes to the server once, and never again.
Serve order, and the 10-10 switch
Service alternates every 2 points (Law 2.13.3) — so you serve twice, then your opponent serves twice, throughout the game.
That changes in two situations. If both players reach 10-10, or if the expedite system comes into force, the order stays the same but each player serves only one point in turn. Since a game is won by the first to 11 unless both reach 10, at which point you need a two-point lead (Law 2.11.1), the single-serve rule stops a long deuce being decided by whoever happens to be serving.
Net touches: it’s a let, not a loss
If your serve clips the net assembly and still lands correctly, you have not lost the point. The rally becomes a let — Law 2.5.3 defines a let simply as “a rally of which the result is not scored”. You take the serve again, with no penalty and no limit on how many times it can happen.
The measurements behind the rules
Useful context for why the numbers are what they are:
| Item | Specification | Law |
|---|---|---|
| Table | 2.74m × 1.525m, 76cm high | 2.1.1 |
| Net height | 15.25cm | 2.2.3 |
| Ball diameter | 40mm | 2.3.1 |
| Ball weight | 2.7g | 2.3.2 |
| Minimum toss | 16cm | 2.6.2 |
| Game | first to 11, two clear at 10-10 | 2.11.1 |
The 16cm toss and the 15.25cm net are not a coincidence worth over-reading, but the near-match is a genuinely useful way to judge your own serve: if the ball does not clearly out-rise the net, it is probably not legal.
Tennis is the instructive contrast: it regulates the toss not at all — the ITF says the ball may be released “in any direction” — because a tennis ball tossed above head height and struck downwards hides nothing. Where a sport has no rule, it usually never had the problem.
The other racket sport with an unusually strict service law is badminton, and it solves the same problem the opposite way round: where table tennis dictates how high you must throw the ball, badminton’s service rules dictate how low you must hit the shuttle. Badminton also requires a diagonal serve in singles — the very thing table tennis does not.
More plain-language breakdowns of how sports actually work are collected in rules and techniques.
Frequently asked questions
Do you have to serve diagonally in table tennis?
Only in doubles. Law 2.6.3 requires the ball to touch the right half court of the server and then the right half court of the receiver — but that clause applies to doubles only. In singles you may serve to any part of your opponent's court, straight down the line if you like. This is the single most common misconception about table tennis.
How high do you have to throw the ball when serving?
At least 16cm after it leaves your palm. That is roughly the height of the net, which is a useful mental benchmark — the net is 15.25cm. The throw must be near-vertical and without spin, and the ball must fall without touching anything before you strike it.
Can you hide the serve in table tennis?
No. Under Law 2.6.4 the ball must not be hidden from the receiver by the server, their doubles partner, or anything they wear or carry, at any point from the start of the service until it is struck. Law 2.6.5 adds that the free arm and hand must be removed from the space between the ball and the net as soon as the ball is thrown.
What happens if you serve illegally?
Your opponent scores a point (Law 2.10.1.1). There is one exception: if the umpire is genuinely unsure about a serve's legality, they may interrupt play and warn the server once per match. After that warning, any serve by that player or their partner that is not clearly legal is judged incorrect and costs a point.
How many serves do you get in table tennis?
Two — service alternates after every 2 points. That changes at 10-10 or under the expedite system, where each player serves only one point in turn.
Can the serve touch the net in table tennis?
Yes, and it does not cost you the point. If an otherwise good service touches the net assembly on its way over, the rally is a let — it simply is not scored, and the serve is taken again. A let is defined in Law 2.5.3 as a rally whose result is not scored.