A part in PartsBox is not the same as its stock. The part is the definition — the MPN, the footprint, the datasheet. The stock is what you physically have: how many, in which locations, and at what cost. Keeping them separate means a part with zero stock still earns its place, showing what needs ordering and matching a BOM line, while the parts you hold carry an exact count.
Stock lives in storage locations, and one part can sit in several at once. A full reel goes on a shelf, a strip of cut tape goes in a compartment box, and PartsBox tells you the quantity in each. A storage location is whatever suits you — a room, a shelf, a box, or one compartment in a grid — so you place a new shipment wherever it fits and let PartsBox remember where it is, instead of sorting inventory by component type. Stock held at a contract manufacturer is just another location, so on-site and off-site quantities stay visible separately.
A part can also have a default storage location: PartsBox pre-selects it whenever you add stock, and you can mark it as mandatory, so a controlled part can only land in its designated bin.
Quantities are recorded in the part's unit of measure: a whole number of pieces for most parts, or 2.5 meters, or 500 grams for a measured one. Parts you have ordered but not yet received show as ordered stock, kept apart from what is on hand, so you can tell what is on the shelf from what is on the way.
Set a low-stock warning per part, and PartsBox flags the part and lists it in a low-stock report when it drops below the threshold, updating the moment anyone adds or removes stock.
Stock history is a permanent record. You add stock when parts arrive and remove it as they are used, and every operation is kept, with who did it and when. You can remove the most recent entry, but older entries cannot be edited or deleted — PartsBox records what actually happened, so the count you see is the count you have.
When a physical count disagrees with the database, adjust the count instead of rewriting history: select one or many batches in a location and set the real quantities, and the adjustment is recorded like any other operation. Add, remove, move, and count stock by scanning a part, a bin, or a distributor barcode.
Stock, storage locations, and low-stock warnings are in every plan, including the free Maker plan. Lot control, which tracks each reel or batch as a distinct lot with its own cost and source, is on the Control plan.