What is the legal limit for a seller of alcohol?

The prohibition of alcohol is not limited to drinking it, but extends to everyone who contributes to it through selling, buying, or preparing it. All of these individuals are deserving of damnation and are committing a forbidden act. Ibn Umar (may Allah be pleased with them both) narrated that the Messenger of Allah (peace be upon him) said: "Allah has cursed alcohol, its drinker, its server, its seller, its buyer, its presser, the one for whom it is pressed, its carrier, and the one to whom it is carried." Narrated by Abu Dawud.

There is no prescribed punishment (hadd) in Islamic law for the seller of alcohol, but the ruler may impose a discretionary punishment (ta'zeer) on him and spill the alcohol. The ruler may also break the containers in which the alcohol is held as a deterrent.