What does it mean if a ship is classed by a non-IACS society?

IACS and non-IACS class, briefly

There are many classification societies in the world. Twelve of them are members of the International Association of Classification Societies (IACS): ABS, Bureau Veritas, China Classification Society, Croatian Register, DNV, Indian Register, Korean Register, Lloyd's Register, ClassNK, Polish Register, RINA and Türk Loydu. Together they class 60,223 ships in the IACS Vessels in Class dataset (snapshot 30 September 2026). See what is IACS for the full list and ship counts.

Every other society is, by definition, non-IACS. The group is very mixed. It includes national societies that class domestic or regional fleets, societies that specialise in smaller ships or particular trades, and newer organisations. Some are authorised by several flag states as recognized organizations. Others have a much thinner track record. Being outside IACS does not, on its own, say which of these a society is.

Why it is a due-diligence question

The issue is not that non-IACS class is improper. It is that IACS membership is the shorthand that most commercial contracts use, so a ship outside it falls outside the default.

• Charter parties commonly require the ship to be classed with an IACS member for the whole period. A ship with non-IACS class may need a specific waiver. See class checks for charter vetting.
• Insurance. Hull and machinery policies and P&I club rules usually set class requirements, often by reference to IACS. Underwriters may price or restrict cover differently. See class checks for marine insurance.
• Finance. Loan agreements typically require class with an acceptable society, often defined as an IACS member.
• Port state control. Regional regimes publish performance tables for recognized organizations based on inspection results. A ship's RO can affect how it is targeted for inspection.
• Sanctions and KYC. A move from IACS to non-IACS class, especially on an older tanker, is one of the patterns compliance teams look at when assessing shadow fleet risk. It is an indicator to investigate, not evidence. See class checks for sanctions and KYC and shadow fleet class red flags.

The practical questions are the same in each case: which society classes the ship now, which flags recognise that society, when and why the ship left its previous society, and whether any surveys or conditions of class were outstanding at the time.

What the numbers show: 431 transfers to non-IACS class

When an IACS member withdraws class, it records a reason. In the 30 September 2026 snapshot, 431 ships carry the reason Transfer of class to a non-IACS society. For comparison, 1,316 carry Transfer of class to another IACS member, and 4,848 ships in total have status Withdrawn.

By the IACS society the ship left:

These figures describe where ships came from, not anything about the society they went to. They also depend on how each society records reasons. Some societies use by society for other reasons widely (3,645 ships across the dataset), so a ship that ended up with non-IACS class may sit under a different reason. Read the table as a floor, not a full count.

What the IACS data can show

The IACS dataset covers only ships classed by the 12 members. For a ship that has left IACS, that still tells you something useful, because the last IACS record usually stays in the file:

• class: the IACS society the ship left.
• status: typically Withdrawn.
• reason_for_status: for example Transfer of class to a non-IACS society, Survey overdue or Owner's request for other reasons.
• date_of_latest_status: when that change was recorded.
• date_of_survey and date_of_next_survey: the survey position at the time, where filled in.

So for a ship that was IACS-classed and moved on, you can see when it left, which society it left and the recorded reason. A withdrawal for Survey overdue followed by a move elsewhere reads differently from a planned transfer at a renewal survey. The status codes guide explains each value, and transfer of class covers how moves between societies normally work.

What the IACS data cannot show

• The new society. The record does not name the non-IACS society the ship moved to. You need the ship's current class certificate, the owner, or another source for that.
• Ships never classed by IACS. A ship that has always been with a non-IACS society is simply absent. A lookup returns no record. Absence means no IACS record, not that the ship is unclassed.
• Current condition. The last IACS record is a snapshot of the past. It says nothing about surveys done since the ship left.
• History beyond the latest status. Each record carries the latest status change, not a full timeline. Earlier moves may not be visible.
• Instant updates. IACS updates its file periodically and Vessel Class Finder refreshes weekly, so a very recent change may not show yet.

For those reasons, a missing or Withdrawn record should lead to a document request, not a conclusion.

A practical check

1. Look up the IMO number in the IACS data. The free lookup takes one IMO at a time, for example IMO 9811000, which returns ABS, Delivered. For a fleet or a deal list, the API takes up to 100 IMOs per request.
2. If the ship is in class with an IACS member, record the society, status and next survey date.
3. If it shows Withdrawn with a transfer to a non-IACS society, note the date and the society it left, then ask the owner for the current class certificate and the name of the new society.
4. If there is no record, ask who classes the ship and check which flags recognise that society as a recognized organization.
5. Check whether your charter party, policy or loan terms require IACS class, and whether a waiver is needed.
6. Keep class status alongside, not instead of, sanctions screening, ownership checks and AIS review.

For the full lookup workflow, see how to check vessel class status.

Frequently asked questions

Related

• What is IACS?
• What class red flags are associated with the shadow fleet?
• What is a transfer of class and why do ships change classification society?
• Vessel class checks for sanctions and KYC screening
• All articles