# Law 12: Ball Touches a Line (ITF Rules of Tennis)

Tennis · Law 12: Ball Touches a Line · Insporta Book (https://book.insporta.app/tennis/laws/law-12-ball-touches-a-line/)

A ball that touches a line counts as touching the court that line bounds, so a line is part of its court.

## 12.121 Ball Touches a Line

Which court a line belongs to, in singles and in doubles, for serves and rallies.

### Test 1: Balls on the lines

- Lines belong to the court they mark out. (Source: ITF Rules of Tennis 2026, Rule 12)
- Touching any part of the line counts as touching the court. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- The service line is part of the service court it bounds. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- The centre service line bounds both service courts, so it is in for each. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- In singles the court is bounded by the singles sidelines; the doubles sideline is outside it. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- In doubles the court runs to the doubles sideline, which is part of it. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- The doubles court includes the alleys, up to and including the doubles sidelines. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- The singles sideline is the last in-place; the alley and beyond are out. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- In doubles all three are inside the court; in singles the doubles sideline is out. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)
- Only A touches the singles court; in singles the alley and the doubles sideline are out. (Source: ITF Rules of Tennis 2026, Rule 12 with Rule 1)

Sources: ITF Rules of Tennis 2026, Rule 12 (paraphrased in original wording; original questions authored from the Rules, not reproduced)

Take the tests: https://insporta.app/try?utm_source=book&utm_medium=referral