ESP Code or IACS Z10: which one applies to my ship?
Both apply to the same ship, and they do not conflict. The ESP Code is the IMO instrument the flag state enforces through SOLAS; UR Z10.1, Z10.2, Z10.4 and Z10.5 are the IACS versions the class surveyor works to. If your ship is a bulk carrier or an oil tanker, you are inside the ESP Code. Everything else is class rules plus the Z7 family.
The short answer
- Both. The ESP Code is IMO and mandatory through SOLAS chapter XI-1; the Z10 family is IACS and is what the class surveyor and the office actually hold in their hands. The extents are the same.
- Inside the ESP Code: self-propelled bulk carriers and self-propelled oil tankers of 500 gross tonnage and above. Nothing else.
- Outside it: chemical tankers, gas carriers, general dry cargo ships, container ships, asphalt carriers and every other type — class rules plus UR Z7, Z7.1, Z7.2 or Z10.3.
- Below 500 GT: outside the ESP Code, still inside the IACS UR — the URs carry no tonnage floor.
- 1 July 2024: MSC.525(106) moved the ballast tank coating trigger from POOR to less than GOOD, and added double-side-skin void spaces for bulk carriers over 20 years and 150 m.
Two documents, one set of numbers
The ESP Code came out of the IMO Assembly, not the class societies. It replaced the enhanced-survey guidelines of resolution A.744(18), which the 1994 SOLAS Conference made mandatory by putting regulation XI-1/2 into the Convention. The 2022 amendment instrument repeats the position: the Code is mandatory under SOLAS chapter XI-1 and is amended through article VIII(b) and regulation XI-1/2. A.1049(27) + MSC.525(106)
That is why the Code reads oddly to anyone used to class rules. It is written throughout in should, not shall — it was drafted as guidance and then made compulsory from outside by the SOLAS regulation. The enhanced survey itself is not a separate visit either: the Code says the surveys are carried out during the surveys prescribed by SOLAS regulation I/10, which is the Cargo Ship Safety Construction survey cycle. A.1049(27) §1.1.7
The IACS side is built the other way round. Each UR opens by saying its requirements are additional to the classification requirements for the rest of the ship, and sends you to Z7 for everything outside the cargo length area. The UR is a class rule; the class society applies it to every ship on its books, and when that society is a recognised organisation acting for the flag, the same survey discharges the SOLAS obligation. UR Z10.1–.5 §1.1.2
The numbers line up because the traffic runs both ways. The Code's technical-assessment annexes cite IACS documents as their references, and the 2024 amendments refreshed those citations to IACS Recommendation 76 for bulk carriers and Recommendation 96 for double-hull tankers. Going the other way, the rule that gauging in close-up areas is taken at the same time as the close-up survey is stated in the same terms in the Code and in all five URs. MSC.525(106) ¶6, 13, 18
Which ships the ESP Code covers
Four application clauses, one at the head of each part. All four carry the same two conditions: self-propelled, and 500 gross tonnage and above.
- Annex A Part A — bulk carriers, other than those that meet the double-side skin definition in Part B. §1.1.1
- Annex A Part B — double-side skin bulk carriers: single deck, topside and hopper side tanks, dry bulk cargo, and every cargo hold bounded by a double-side skin whatever the width of the wing space. Ore carriers and combination carriers are named as included. §1.1.1 + §1.2.1
- Annex B Part A — double-hull oil tankers: cargo tanks protected by a double hull running the full length of the cargo area, double sides and double bottom carrying water ballast or void space. §1.1.1 + §1.2.1
- Annex B Part B — oil tankers that are not double-hull. §1.1.1
Hybrid bulk carriers are split, not assigned. A ship with some single-side-skin holds and some double-side-skin holds is surveyed under Part B for the double-side holds and their wing spaces, and under Part A for the single-side holds. IACS says the same thing in the same words. §1.1.6 / §1.1.4
Within a covered ship the Code does not reach the whole hull, and the two annexes do not list the same spaces. On a bulk carrier it reaches the hull structure and the piping over the cargo holds, the cofferdams and pipe tunnels, and those void spaces and fuel oil tanks that lie inside the cargo length area, plus every ballast tank; pump-rooms are not named. Annex A §1.1.2 On an oil tanker the set changes: cargo tanks, pump-rooms, cofferdams and pipe tunnels, the void spaces inside the cargo area, and again every ballast tank; fuel oil tanks are not named. Annex B §1.1.2 The engine room, the accommodation and the fore and aft ends outside those spaces are not ESP scope — they are class scope, under Z7. UR Z10.2 §1.1.2
Which ships fall outside it
The Code names two ship types and no others. Everything that is not a bulk carrier and not an oil tanker under those definitions is outside it, and is surveyed to the class rules with the relevant IACS UR on top. In practice that is:
- Chemical tankers — self-propelled ships with an IMO certificate of fitness for dangerous chemicals in bulk. UR Z10.3, not the ESP Code. Where a chemical tanker has both integral and independent tanks, Z10.3 covers only the part of the cargo length with integral tanks. UR Z10.3 §1.1.1
- Liquefied gas carriers — UR Z7.2. A combined gas carrier / chemical tanker with independent tanks inside the hull is surveyed as a gas carrier. UR Z10.3 §1.1.1 → Z7.2
- General dry cargo ships — UR Z7.1.
- Container ships, ro-ro, reefers, car carriers, everything else self-propelled — UR Z7 alone, plus the society's own rules.
- Asphalt carriers and similar — the oil tanker definition as amended in 2024 excludes ships that carry oil in independent tanks which are not part of the ship's hull, and names asphalt carriers as the example. MSC.525(106) ¶19
- Non-self-propelled units, and bulk carriers or tankers under 500 GT — outside the ESP Code by its own application clause. This is where the two documents genuinely diverge: no UR Z10 application clause carries a tonnage threshold, so class still applies the full UR to a small self-propelled tanker the ESP Code never touches. UR Z10.1–.5 §1.1.1
Combination carriers sit in both families and pick up requirements from both. A single-skin combination carrier is a bulk carrier under Z10.2 with additional requirements from Z10.1; a double-skin one takes Z10.5 with additions from Z10.1 or Z10.4 as applicable. Z10.2 / Z10.5 §1.2.1 fn.1
The mapping table
The annex numbering is not shared. The same subject sits under a different number in each part of the Code, and under a Roman-numeral table in the UR. This is the table to have open when someone quotes you a clause over the phone.
| Ship type | ESP Code | TM extent in the Code | IACS UR | TM extent in the UR |
|---|---|---|---|---|
| Bulk carrier, single-side skin | Annex A, Part A | Annex 2 renewal; Annex 10 substantial corrosion; Annex 11 vertically corrugated transverse watertight bulkhead between holds 1 and 2; Annex 14 procedural requirements for thickness measurements; Annex 15 side shell frames | Z10.2 R37 | Table II special survey; Table VIII substantial corrosion; Annex V side shell frames |
| Bulk carrier, double-side skin | Annex A, Part B | Annex 2 renewal; Annex 10 substantial corrosion in the cargo length area | Z10.5 R20 | Table II special survey; Table IV substantial corrosion; Table V intermediate |
| Oil tanker, double hull | Annex B, Part A | Annex 2 renewal; Annex 4 substantial corrosion | Z10.4 R18 | Table II special survey; Table IV substantial corrosion; Table V intermediate |
| Oil tanker, not double hull | Annex B, Part B | Annex 2 renewal; Annex 4 substantial corrosion | Z10.1 R25 | Table II special survey; Table IV substantial corrosion |
| Chemical tanker | not covered | — | Z10.3 R20 | Table II special survey; Table IV substantial corrosion |
| General dry cargo ship | not covered | — | Z7.1 R15c1 | Table II special survey; Table III additional gauging in way of substantial corrosion |
| Liquefied gas carrier | not covered | — | Z7.2 R8 | Table II special survey; Table V additional gauging in way of substantial corrosion |
| Any other self-propelled vessel, and the non-ESP part of every ship | not covered | — | Z7 R29c1 | Table 1 |
Two traps in that table. The annex numbers are not shared between the parts of the Code: in Annex A Part A the corrugated-bulkhead gauging guidelines are Annex 11 and the procedural requirements for thickness measurements are Annex 14, while in Annex A Part B the procedural requirements are Annex 12 and Annex 11 is the hatch cover securing strength. A.1049(27) Annex A lists And in Z7.1 and Z7.2 the table called Table I is the close-up survey table, not a thickness measurement table. Thickness measurement is Table II in both; in Z7.2, Table III is a second close-up table, for the intermediate survey. Z7.1 / Z7.2 Enclosures
Sources for the whole table: A.1049(27) Contents UR Z10.1–.5 Enclosures · Z7, Z7.1 and Z7.2 table references carried from K3.7.
What the 2024 amendments changed
MSC.525(106) was adopted on 10 November 2022, deemed accepted on 1 January 2024 and in force from 1 July 2024. It runs to 22 numbered items across both annexes. MSC.525(106) ¶2–3
| Clause replaced or added | Before | After 1 July 2024 |
|---|---|---|
| Ann.A Pt A §2.3.1 Ann.A Pt B §2.3.1 | Ballast tanks other than double bottom: annual examination triggered when hard coating is POOR and not renewed | Same tanks, trigger is now less than GOOD — a FAIR tank is now on annual examination. Gauging as the surveyor deems necessary |
| Ann.A Pt A §4.2.1.2–.3 Ann.A Pt B §4.2.1.2–.3 | Intermediate survey, BC 5–10 years: extension to sister tanks and annual examination both keyed to POOR | Both keyed to less than GOOD. Double-bottom ballast tanks keep the softer wording — they may be examined annually |
| Ann.A Pt B §2.3.4 (new) | no requirement | Double-side skin void spaces bounding cargo holds, DSS bulk carriers over 20 years and 150 m and upwards: coating examined; annual examination if POOR and not renewed |
| Ann.A Pt B §3.7 (new) | no requirement | Annual survey item for the same void spaces, triggered by the renewal and intermediate survey results. Substantial corrosion found there expands the gauging under annex 10, and the expansion is completed before the survey is credited. Carve-out in the same paragraph: a bulk carrier built under the IACS Common Structural Rules may leave that annual gauging out, provided the protective coating went on to the coating manufacturer's own requirements and is being kept in good condition |
| Ann.B Pt A §2.6.1 Ann.B Pt B §2.6.1 | Renewal survey tank pressure testing requirements | Adds 6 conditions under which crew-performed cargo tank testing may be accepted, including a procedure reviewed in advance and testing no more than 3 months before the overall or close-up survey is completed |
| Ann.B Pt A §1.2.1 Ann.B Pt B §1.2.1 | Definitions of double-hull oil tanker and oil tanker | Both now require the cargo tanks to form an integral part of the hull. The Part B definition adds an express exclusion for ships carrying oil in independent tanks that are not part of the hull, naming asphalt carriers |
| Ann.B Pt A condition evaluation report Ann.B Pt B condition evaluation report (tank corrosion prevention system, text after note 3) | Where the coating is entered as anything below GOOD, the note calls for extended annual surveys, and for that to be recorded in part 9 of the report contents | For ballast tanks, coating less than GOOD means the tanks shall be examined at annual surveys. So the tanker parts move too, though not by the same route as the bulk carrier parts: the tanker survey clause already read less than GOOD in 2011, and it is the report note that is brought into line with it and narrowed to ballast tanks |
Source for the whole table: MSC.525(106) ¶1–22 compared clause by clause with A.1049(27) §2.3.1, §4.2.1
The rest of the instrument is reporting. The Condition Evaluation Report gains a memorandum line for ballast tanks under annual examination because of coating breakdown, and for double-side skin bulk carriers its corrosion-prevention part is renamed and extended so that all ballast tanks, all cargo holds and all double-side skin void spaces are listed with their coating condition. The oil tanker parts are touched in the same forms, and not only for form's sake: that is where their annual-examination note changed, the last row of the table above. The GOOD / FAIR / POOR standard itself did not move. GOOD still means minor spot rusting and nothing else. FAIR still means the coating has broken down locally, at stiffener edges and at weld connections, or light rust runs to 20% or more of the area you are judging, but has not gone as far as POOR. POOR still means the coating has broken down generally over 20% or more of that area, or hard scale sits on 10% or more of it. MSC.525(106) ¶11–12
One thing MSC.525(106) did not do is introduce the rule that gauging is taken at the same time as the close-up survey. That requirement has been in the Code since 2011, at §1.5 of every part, and in the URs at §1.4 (numbered 1.4.1 in Z10.3). If someone tells you it is a 2024 change, they are reading a summary, not the instrument. A.1049(27) §1.5
Remote inspection techniques: the split is real, and it is closing
This is the clearest place where the ESP and non-ESP sides of the IACS catalogue differ today. UR Z7, Z7.1, Z7.2 and Z10.3 all carry a clause letting the attending surveyor accept a remote inspection technique in place of a close-up survey, worked to IACS Recommendation 42 and agreed in advance with the society. UR Z10.3 §1.5 · Z7 §1.6
The four ESP-mirroring documents — Z10.1, Z10.2, Z10.4 and Z10.5, all at their February 2023 revisions — carry no such clause, because the Code they mirror does not have one. A chemical tanker can be close-up surveyed by drone where the surveyor agrees. A bulk carrier under the same class, on the same day, cannot. UR Z10.1, .2, .4, .5 §1
Forward-looking note, no source chip yet. Amendments to the ESP Code allowing remote inspection techniques for close-up survey and thickness measurement were adopted in 2026 at MSC 111, with entry into force on 1 January 2028. The text is not yet in the consolidated Code and is not in the amendment instrument this page was checked against, so nothing here is cited to it. A reviewer must add the resolution number and clause references before this page is published, and must confirm whether the entry-into-force date has held.
Until that text lands, plan an ESP ship as though every close-up position needs staging, a raft or a cherry picker, and gauging taken by hand at the same visit.
Getting the right template on the first try
Draft Operator picks the extent tables from the ship type and the survey number, so a double-side skin bulk carrier does not come back on a single-side skin sheet — ⊞ Job → Ship type → Annex/UR.
Open Draft OperatorSources
- A.1049(27)IMO Res. A.1049(27) — 2011 ESP Code, adopted 30 Nov 2011official text ↗
- MSC.525(106)IMO — Amendments to the 2011 ESP Code, adopted 10 Nov 2022, in force 1 Jul 2024official text ↗
- UR Z10.1 Rev.25IACS — Hull surveys of oil tankers, Feb 2023official text ↗
- UR Z10.2 Rev.37IACS — Hull surveys of bulk carriers, Feb 2023index entry →
- UR Z10.3 Rev.20IACS — Hull surveys of chemical tankers, May 2022official text ↗
- UR Z10.4 Rev.18IACS — Hull surveys of double hull oil tankers, Feb 2023official text ↗
- UR Z10.5 Rev.20IACS — Hull surveys of double skin bulk carriers, Feb 2023official text ↗
- UR Z7 Rev.29 Corr.1IACS — Hull classification surveys, May 2024official text ↗
Class-society and IMO documents are indexed and linked, never re-hosted. Where a class rule is stricter than the IACS baseline, the class rule governs.