Since 1 January 2026, a car powered by a lithium-ion battery is no longer declared at sea under UN 3171. It goes under UN 3556 (lithium-ion), and its cousins UN 3557 (lithium metal) and UN 3558 (sodium-ion) cover other battery types. For an importer this means one practical thing: tell your forwarder the exact battery type of every EV or plug-in hybrid before booking, and check that the booking, the bill of lading and the dangerous goods declaration all carry the same entry.
👉 Importing EVs or plug-in hybrids? Ask us on WhatsApp · How the China car export chain works →
Why are electric cars treated as dangerous goods at sea?
Ships carry dangerous goods under the International Maritime Dangerous Goods (IMDG) Code. The IMO explains that SOLAS chapter VII sets the mandatory rules for dangerous goods carried in packaged form, and the IMDG Code is an extension of those rules; it has been mandatory under SOLAS since 1 January 2004, although some parts remain recommendatory. The Code covers packing, container traffic, stowage and the separation of incompatible goods.
A battery-powered vehicle sits in Class 9, miscellaneous dangerous goods. That does not mean the car is banned. It means the shipment has to be identified correctly, and the carrier decides how and where it can be loaded. If you are still choosing between ship types, RoRo vs container shipping for cars from China explains the basic difference.
What changed on 1 January 2026?
Amendment 42-24 to the IMDG Code was available on a voluntary basis from 1 January 2025 and became mandatory on 1 January 2026. Britannia P&I Club, West of England P&I Club and Maersk all give the 2026 date.
The changes that matter to a car importer, as described by these sources:
- Three new entries. UN 3556 for vehicles powered by lithium-ion batteries, UN 3557 for lithium metal batteries and UN 3558 for sodium-ion batteries, all Class 9.
- UN 3171 is narrower. Maersk’s customer advisory of 6 January 2026 says the generic UN 3171 entry is no longer permitted for lithium or sodium-ion battery powered vehicles. West of England describes UN 3171 as now limited to vehicles and equipment with wet batteries and similar types.
- Special provisions were rewritten. Britannia reports that special provisions 961 and 962, which deal with how such vehicles are carried, were amended to include the new entries.
If a template, a booking form or a forwarder’s checklist still says UN 3171 for a lithium-ion car, it is out of date.
Which UN number does my car use?
| Battery in the vehicle | Entry under IMDG 42-24 |
|---|---|
| Lithium-ion | UN 3556 |
| Lithium metal | UN 3557 |
| Sodium-ion | UN 3558 |
| Wet battery and similar | UN 3171 (narrower scope) |
The table shows the entries, not a ruling on your car. Whether a particular battery electric, plug-in hybrid or range-extender model falls under one entry or another depends on its battery, and the forwarder or the shipping line confirms it. We do not give a number for a specific model here.
What do I need to check before booking?
Maersk’s advisory points shippers to three things, and they are a good checklist for any line:
- The correct UN number on the booking.
- Placarding for containers. Maersk recommends placards on all four sides of a container subject to special provision 962, because ports interpret the rule differently, and encourages customers to check this before gate-in.
- Matching paperwork. The booking data, the bill of lading and the dangerous goods declaration should show the same entry and description. The wider document set is in the car export documents checklist. Payment terms that depend on those documents are in letter of credit vs T/T.
Maersk also warns that cargo not meeting the new requirements may be delayed, rejected or penalised. That is a carrier statement, not a general rule for every line, but it is reason enough to get the entry right before the car reaches the port.
Is RoRo or a container easier for an electric car?
There is no clean answer from the sources. Some commentary says lithium-battery vehicles stowed in designated vehicle spaces on a RoRo ship are handled differently from boxed cars; other commentary says a car inside a container is always Class 9. These summaries contradict each other, and we could not match them against the IMDG text itself, so we draw no conclusion.
What you can do is ask the line directly, in writing:
- Does this line accept battery electric and plug-in hybrid cars on this route and in this port?
- On RoRo or in a container, which declaration does it want?
- Does it ask for battery documents or an inspection report before accepting the booking?
Lines, routes and ports differ, so the same car can be accepted by one carrier and declined by another. Our Nansha RoRo terminal guide and freight forwarder quote breakdown help you frame those questions to a forwarder.
What should an importer do differently for EVs?
- State the powertrain at the first inquiry. Battery electric, plug-in hybrid and range-extender cars should be identified as such from the start, not after the booking is made.
- Do not accept an old UN 3171 template for a lithium-ion car.
- Never ask a forwarder to describe a battery car as ordinary cargo. A false description is a bigger problem than a declaration that costs time.
- Photograph the car before loading. If there is damage, condition evidence at origin matters for claims; see marine cargo insurance and claims for cars from China and remote car inspection before paying.
- Plan for more lead time on the first EV shipment with a new forwarder, because the line may ask for extra information.
- Check the destination as well. Rules at the receiving port are separate from the ship rules; see demurrage and storage charges and shipping cars from China to African ports.
Where can I read more about electric car imports?
The rule applies to every route, so it matters wherever you ship EVs or plug-in hybrids. For Ethiopia, see importing electric cars from China to Ethiopia, CIF Djibouti for Ethiopia and the best EVs for ride-hailing in Addis Ababa. For specific models, see BYD Dolphin vs Seagull or Qin Plus vs Seal 05 DM-i for plug-in hybrids. The first shipment is also covered by how to ship just one car and the 2026 import guide for dealers.
FAQ
Can I still use UN 3171 for my electric car?
Not if the car runs on a lithium-ion or sodium-ion battery. Since 1 January 2026 those vehicles are declared under UN 3556 (lithium-ion) or UN 3558 (sodium-ion), and UN 3557 covers lithium metal. UN 3171 is kept for wet battery vehicles and similar types.
Do plug-in hybrids count as battery-powered vehicles?
They carry a battery as well as a fuel tank, and sources differ on how the details apply. Give the forwarder the model, the battery type and the fuel tank state, and ask the line for a written answer.
Will a shipping line refuse my electric car?
It can. Each line sets its own acceptance rules and ports apply them differently. Ask before you book, not after.
Is this article a basis for filing the declaration?
No. It summarises public notices from a carrier and two insurers. The declaration itself follows the IMDG Code text and the requirements of your line and forwarder.
Does this change the price?
We do not quote freight rates in articles. Ask your forwarder what, if anything, a dangerous goods declaration adds on your route.
Sources: Maersk customer advisory “IMDG Code 42-24: Battery Vehicle Changes” (6 January 2026; UN 3171 no longer permitted for lithium or sodium-ion vehicles, new entries, four-side placarding recommendation under SP 962, possible delay, rejection or penalty); Britannia P&I Club, “International Maritime Dangerous Goods (IMDG) Code Amendment 42-24” (December 2025; new entries, amended SP 961/962, voluntary from 2025 and mandatory from 1 January 2026); West of England P&I Club, “SOLAS – Amendments to the IMDG Code (Amendment 42-24)” (September 2024; UN 3171 limited to wet battery vehicles and similar, mandatory 1 January 2026); IMO, page on the IMDG Code (SOLAS chapter VII, mandatory since 1 January 2004, parts recommendatory). Checked November 2026. The narrower scope of UN 3171 is from West of England only; the SP 961/962 amendment is from Britannia only; the four-side placarding is Maersk’s recommendation, not a universal rule. The IMDG 42-24 text itself was not read, so the RoRo versus container treatment of battery cars, the exact conditions of SP 961/962 and the declaration of hybrid vehicles are left open. Photo: FPTI / Wikimedia Commons, CC0. No freight rates are quoted. Photo: FPTI / Wikimedia Commons, CC0.