When do we change ends, and what if we forget or serve out of turn?

Under Laws 2.13 and 2.14 of the Laws of Table Tennis (ITTF Statutes 2026):

Changing ends

• The player or pair starting at one end in a game starts at the other end in the next game.
• In the last possible game of a match (e.g. the fifth game of a best of five), players change ends when either side first reaches 5 points.

Mistakes

• If someone serves or receives out of turn, the umpire stops play as soon as it's noticed. Play resumes with the correct server and receiver at the score reached, following the order set at the start of the match.
• If players haven't changed ends when they should, the umpire stops play as soon as it's noticed and they move to the correct ends at the score reached.
• All points scored before the error was discovered still count.