IMPA vs ISSA Codes: Differences and When to Use Each

Procumare · July 7, 2026 · 5 min read

Ship supply has two catalogue standards, and almost every purchasing team ends up asking the same question: should our requisitions carry IMPA codes, ISSA codes, or both? The short answer — use whichever your organisation has standardised on, quote both when you have them, and never rely on free text alone. Here is the longer answer.

Two Associations, Two Catalogues

The two catalogues overlap heavily in coverage: provisions, cabin and deck stores, engine stores, safety equipment and more. Many products can be referenced through either system, and experienced suppliers recognise both.

Practical Differences That Matter

1. Who standardised first in your workflow. If your fleet's requisition templates and purchasing software are built around MSG, IMPA is your primary key — that is the common case on the buyer side. Suppliers who grew up on the chandler side often stock-keep by ISSA.
2. Item granularity differs. The catalogues sometimes slice the same product family differently (pack sizes, variants). When converting between systems, verify the description — don't assume one-to-one mapping.
3. Neither covers everything. Technical spares tied to specific equipment (maker, model, serial number) live outside both catalogues; those lines need part numbers and documentation instead. See our RFQ template guide for how to structure such lines.

What to Put in Your RFQ

• Have both codes? Include both. It costs nothing and removes all ambiguity for whichever catalogue the supplier uses.
• Only one code? Use it, plus a clear description with unit and pack size. Professional suppliers cross-reference routinely.
• No code? Description + brand/model + photo. A photo answers more specification questions than a paragraph of text.

Codes in Digital Procurement

Procurement platforms use catalogue codes as the backbone of item master data: requisition lines link to codes, supplier quotes attach to the same line, and price history accumulates per code across orders. That turns the IMPA/ISSA discipline from a documentation habit into automatic, comparable data — including when you source from cost-competitive hubs like Turkey (see our Turkey ship supply guide).