IMPA vs ISSA: Comparing Marine Coding Systems

Two major coding systems are used to identify products in marine supply: IMPA and ISSA. Both serve the same purpose — identifying a product uniquely without language barriers — but differ in structure and origin. This article explains the difference between IMPA and ISSA.

What Is IMPA?

IMPA (International Marine Purchasing Association) is a coding system developed from the buyer/purchasing perspective. Its Marine Stores Guide lists more than 50,000 items with 6-digit codes and is the most widely used system worldwide. See our IMPA code guide for details.

What Is ISSA?

ISSA (International Ship Suppliers & Services Association) is a coding system published by the ship suppliers' association. The ISSA Ship Stores Catalogue groups products by its own structure, reflecting more of the supplier's perspective.

Key Differences

• Origin: IMPA from a purchasing association, ISSA from a suppliers' association.
• Code structure: different grouping and numbering logic; the same product may have different codes in each.
• Prevalence: IMPA is more dominant in international supply; many suppliers support both.

Which Should You Use?

In practice ships and suppliers often use both, but the parties should agree upfront which system applies for order clarity. e-ShipSupply's catalogue is based on IMPA codes; search by IMPA code to reach supplier listings.

Frequently Asked Questions

Are IMPA and ISSA codes different for the same product?

Yes. The two systems have different structures; the same product may be listed under different codes.

Which is more widely used?

IMPA is more dominant in international supply, though many suppliers support both.