Yes. Merchandise held for sale (ʿurud al-tijarah) is subject to zakat, based on the general command to spend from the good things one has earned, and this was the practice of the Companions such as ʿUmar and Ibn ʿAbbas. At the end of each lunar year (hawl) you value your saleable stock at its current market price, add cash and receivables, subtract due debts, and if the total reaches the nisab (the value of roughly 85 grams of gold) you pay 2.5% (rubʿ al-ʿushr). Fixed assets used to run the business, such as shelving, vehicles, or the premises themselves, are not counted, only the goods intended for resale and the trading capital.
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.