APPENDIX K ITF RULES OF TENNIS 27. CORRECTING ERRORS As a principle, when an error in respect of the Rules of Tennis is discovered, all  points previously played shall stand. Errors so discovered shall be corrected  as follows: a.  During a standard game or a tie-break game, if a player serves from the  wrong half of the court, this should be corrected as soon as the error is  discovered and the server shall serve from the correct half of the court  according to the score. A fault that was served before the error was  discovered shall stand. b. During a standard game or a tie-break game, if the players are at the  wrong ends of the court, the error should be corrected as soon as it is  discovered and the server shall serve from the correct end of the court  according to the score. c. If a player serves out of turn during a standard game, the player who  was originally due to serve shall serve as soon as the error is discovered. However, if a game is completed before the error is discovered the order  of service shall remain as altered. In this case, any ball change to be made  after an agreed number of games should be made one game later than  originally scheduled. A fault that was served by the opponents(s) before the error was  discovered shall not stand. In doubles, if the partners of one team serve out of turn, a fault that was  served before the error was discovered shall stand. A fault that was served by the opponent(s) before the error was  discovered shall not stand. In doubles, if the partners of one team serve out of turn, a fault that was  served before the error was discovered shall stand. d. If a player serves out of turn during a tie-break game and the error is  discovered after an even number of points have been played, the error is  corrected immediately. If the error is discovered after an odd number of  points have been played, the order of service shall remain as altered. e.  During a standard game or a tie-break game in doubles, if there is an error  in the order of receiving, this shall remain as altered until the end of the  game in which the error is discovered. For the next game in which they  are the receivers in that set, the partners shall then resume the original  order of receiving. 458