Is zakat obligatory for the owner of a commercial shop that he rents out, who does not possess a monetary balance at the end of the year, and has exhausted all rental income before the year elapsed?

Zakat (definition) is not obligatory on the property itself, but rather on the income derived from it, subject to two conditions: that the income reaches the nisab (definition) (minimum threshold) either by itself or when combined with other money or trade goods, and that a full hawl (lunar year) passes. If one of these two conditions is not met, Zakat is not obligatory. This is because for wealth on which Zakat is obligatory in its essence and for which the hawl is considered (such as gold, silver, and livestock), the nisab must be present for the entire hawl. If the nisab decreases at any moment, the hawl is interrupted. Accordingly, Zakat is not obligatory for the questioner because the money did not remain with him for a full year.