Lets: broken balls, stray balls and interruptions
A let stops the point and replays it, serve and all, when something outside the players' control gets in the way: a ball from the next court, a split ball, something blowing onto the court. Call it straight away.
What a let is
A let replays the whole point with no penalty. It is there for interruptions nobody on court caused. If it happens during a first serve's point, the server gets both serves again.
The usual reasons
A ball from another court rolling onto yours. A towel, a bag or a person coming onto the court. The ball splitting or going soft during the point. A ball lying on their side that gets hit and moves in a way that could trip someone. If a ball in play simply hits an object lying in the other court, such as a spare ball, and that object does not move in a way that could interfere, the shot is good and play goes on.
Call it at once
Stop and say so the moment it happens. If you keep playing, see how the rally goes and then ask for a let, you have lost the right to it. In refereed matches the umpire decides, and a let asked for without good reason costs the point.
In social games
Without an umpire, each pair calls their own side. When the four of you honestly cannot agree what happened, replay the point. It keeps the game friendly and nobody remembers it five minutes later.
Fragen
What is a let in padel?
A replay of the whole point when something outside the players' control interferes, such as a ball from another court. On the serve, a net cord that lands in the box is also replayed.
Can you call a let after the rally?
No. A let must be called straight away. Play on and you lose the right to it.