ClassNK class status lookup
Nippon Kaiji Kyokai (ClassNK) appears in the IACS data under the code NKK, not "ClassNK". As of 30 September 2026 the IACS dataset lists 10,117 ships classed by ClassNK: 9,009 in class, 74 suspended and 967 withdrawn. Look up any ClassNK-classed ship by IMO number below, or check up to 100 at once through the API.
ClassNK fleet by class status
How the 10,117 ships listed under NKK break down by their latest IACS status:
| Status | Vessels | Share | Meaning |
|---|---|---|---|
| Delivered | 8,379 | 82.8% | In class |
| Reinstated | 382 | 3.8% | In class |
| Reassigned | 248 | 2.5% | In class |
| Suspended | 74 | 0.7% | Not in class |
| Withdrawn | 967 | 9.6% | Not in class |
| No status recorded | 67 | 0.7% | Not stated |
Most common reasons for status changes
The reason recorded with each ship's latest status change, where one is given:
| Reason | Vessels |
|---|---|
| Transfer of class to another IACS member | 489 |
| Survey overdue | 279 |
| Owner's request for other reasons | 169 |
| Sold for recycling (scrap) | 59 |
| Transfer of class to a non-IACS society | 40 |
About ClassNK
- Full name: Nippon Kaiji Kyokai (ClassNK)
- Also known as: ClassNK, NK, Nippon Kaiji Kyokai
- Founded: 1899
- Headquarters: Tokyo, Japan
- IACS code:
NKK - Website: www.classnk.or.jp
Check ClassNK class status through the API
Send IMO numbers to /vessels. Ships classed by ClassNK come back with "class": "NKK":
curl -X POST https://vessel-class-finder-production.up.railway.app/vessels \
-H "x-api-key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"imos": [9321483, 9074729]}'Filter the response on class == "NKK" to find the ClassNK-classed ships in a list, and on status to find any that are suspended or withdrawn.
Check a whole fleet at once
Free API key: 100 lookups a month, up to 100 IMO numbers per request. Paid plans from €49/month.
Get a free API keyFrequently asked questions
How do I check if a ship is classed by ClassNK?
Enter the ship's 7-digit IMO number in the lookup on this page. If ClassNK classes it, the result shows class society NKK, the class status and the last and next survey dates. For many ships at once, use the API with up to 100 IMO numbers per request.
What code does ClassNK use in IACS data?
NKK. The IACS Vessels in Class dataset and this API identify Nippon Kaiji Kyokai (ClassNK) as "NKK".
How many ships does ClassNK class?
As of 30 September 2026, the IACS dataset lists 10,117 ships under ClassNK, of which 9,009 are in class (Delivered, Reinstated or Reassigned), 74 suspended and 967 withdrawn. That makes it number 1 of the 12 IACS members by ships listed.
Is this official ClassNK data?
It is ClassNK's own data as published by IACS in its Vessels in Class dataset, refreshed weekly. It is not a substitute for class certificates or the society's own records, which remain authoritative.
Can I get ClassNK class status through an API?
Yes. POST a list of IMO numbers to /vessels with your API key and each result includes the class society code, status, survey dates and reason for the latest status change. The free tier includes 100 lookups a month.
Other IACS classification societies
Numbers come from IACS's public Vessels in Class dataset and cover only ships classed by IACS members. They are not a substitute for class certificates or the society's own records.