Calling a Ball "Out"

My opponent returned my shot (into the net) THEN called the ball out.

Answer:

Hi,

On hard court, it is required that you call the ball immediately as it lands. Calling the ball out after it has touched the net, is not allowed!

On Clay Court players give margin as you can return and quickly check the bounce mark. Then, if you see the ball was out you can say "out" and show the mark.

Nevertheless, on hard court, the call has to be when the ball bounces.