When do I call a no ball?

Under Law 21 of the MCC Laws of Cricket (2017 Code, 4th Edition 2026), an umpire calls and signals No ball in these cases:

• Feet (21.5): in the delivery stride the bowler's back foot does not land within and not touching the return crease on the side of their stated mode of delivery, or the front foot does not land with some part of the foot (grounded or raised) on the same side of the imaginary line joining the two middle stumps as that return crease and behind the popping crease. If the bowler's end umpire is not satisfied that all three conditions are met, they call No ball.
• Thrown or underarm (21.2, 21.3): the ball is thrown, or delivered underarm without prior agreement.
• Mode of delivery (21.1): the bowler changes their mode of delivery (right or left handed, over or round the wicket) without telling the umpire.
• Breaking the wicket (21.6): the bowler breaks the wicket at any time after the ball comes into play and before completing the stride after the delivery stride, unless the non-striker is dismissed under Law 38.3. This includes clothing or objects falling from the bowler that break the wicket.
• Bounces and rolls (21.7): the ball bounces more than once or rolls along the ground before reaching the popping crease, or first lands or later bounces wholly or partly off the pitch before reaching the line of the striker's wicket.
• Ball stopping or leaving the pitch (21.8): the ball comes to rest in front of the striker's wicket line, or is so far from the pitch that the striker would need to leave it to play. Call No ball and immediately Dead ball.
• Fielder touches the ball (21.9): the delivery touches a fielder's person before it touches the striker's bat or person or passes the wicket (except in the circumstances of Law 27.3). Call No ball and immediately Dead ball.
• Other Laws (21.10): Law 27.3 (wicket-keeper position), 28.4 (limit on on side fielders), 28.5 (fielders encroaching on the pitch), and 41.6, 41.7 and 41.8 (dangerous and unfair bowling).