An IMPA code is a six-digit reference number drawn from the IMPA Marine Stores Guide, the catalogue published by the International Marine Purchasing Association. Each code corresponds to a single, defined marine store item, so that a vessel buyer and a ship chandler on opposite sides of a transaction can refer to exactly the same product, in the same unit of measure, without ambiguity. The Marine Stores Guide catalogues tens of thousands of items in common maritime use, from ropes and gaskets to galley equipment and cleaning chemicals.
How an IMPA code is structured
The six digits are organised by section. The leading digits place an item within a chapter or category of the guide, for example rope and hawsers, rigging equipment, marine paints, or tableware and galley utensils, and the remaining digits identify the specific item within that category. Because the numbering is consistent worldwide, an item ordered under a given IMPA code in one port is the same item under the same code in any other, which is what makes the system valuable for global procurement.
Why IMPA codes matter
Most delays and disputes in ship supply come from vague item descriptions. A requisition that simply reads "gasket" or "cotton waste" can be interpreted several ways; an IMPA code removes that guesswork. When a request for quotation is coded, the chandler quotes against the exact catalogue line, the delivery matches what was ordered, and the invoice reconciles cleanly against the original requisition. Coded requisitions also make it possible to compare quotes from several suppliers line by line, because every supplier is pricing the identical item.
IMPA codes in modern procurement
Traditionally, matching a free-text requisition to the right IMPA codes was slow manual work. Today that step can be automated: software reads an incoming RFQ, resolves each described item to its IMPA code, and flags anything it cannot match with confidence for a human to check. This is the foundation of a structured RFQ-to-quote workflow, and it is why accurate IMPA coding underpins faster, more reliable maritime quoting.
IMPA codes and units of measure
Every IMPA code carries a defined unit of measure, and getting the unit right is as important as getting the code right. An item can be catalogued by piece, by metre, by kilogram, by litre, by roll or by coil, and a quantity that is correct in one unit can be badly wrong in another. Because the unit travels with the code, a coded requisition tells the chandler not just which item is wanted but in what form and measure, which removes a common cause of over- and under-supply. This is one more reason coded RFQs reconcile cleanly from quote to delivery note to invoice.
