Does the CDS Melt and Pour steel rule apply to imports into Great Britain?

By Saurabh Goyal, Founder & CEO of Phlo Systems. Published 16 October 2026.

HMRC's CDS Release 5.3.0.1 takes effect on 22 October 2026 and introduces a set of new document and country codes for declaring the melt and pour origin of steel, where the steel was actually melted and cast into its first solid form, not just where it was last substantially transformed before export. The rule generating those codes is an EU requirement, and it reaches UK trade through Northern Ireland. It does not introduce a new melt and pour declaration requirement for steel moving directly into Great Britain.

The 30-second answer:

• What changed in CDS: Release 5.3.0.1, live 22 October 2026, adds document codes C131 to C139 and country-of-melt-and-pour codes Y376 to Y387 to Appendix 5A, alongside other changes in the same release (additional information codes for Great Britain and Northern Ireland, a TOR01 code validation, and new measurement unit codes).
• Why the codes exist: EU Implementing Regulation 2026/1963 requires importers of certain steel and steel-derivative products to declare the country where the steel was melted and poured, plus its heat number, from 1 October 2026. That EU requirement applies to steel moving into Northern Ireland, which follows EU customs rules under the Windsor Framework.
• What it does not do: it does not create a melt and pour declaration requirement for steel imported directly into Great Britain. The UK government has said it is exploring its own melt and pour reporting requirement as part of its Steel Strategy, but that is a separate, not-yet-implemented policy question, not something CDS Release 5.3.0.1 itself introduces for GB imports.
• Who has to act now: anyone declaring steel or steel-derivative products moving into Northern Ireland from Great Britain or from outside the UK, and the customs agents and forwarders filing those declarations on their behalf.
• Where tradePhlo stands: tradePhlo's Declarations module files CDS import and export declarations today and is being kept current against HMRC's Appendix 5A code changes as they are released, including this one.

What melt and pour origin actually means

Melt and pour origin identifies the country where steel was first produced in liquid form in a furnace and then cast into its first solid shape, a slab, billet, ingot, or finished steel-mill product. That is a different question from where the goods were last substantially transformed, which is the test that normally decides a product's customs origin for tariff and preference purposes. A steel product can be substantially transformed, rolled, coated, or fabricated, in one country while the underlying metal was melted and cast somewhere else entirely, and melt and pour rules exist specifically to capture that earlier step rather than let the last processing country stand in for it.

This distinction is the point of the whole exercise. Rules built around substantial transformation can be satisfied by relatively light processing performed outside the country where the metal was actually made, which is exactly the routing that melt and pour evidence is designed to see through.

Why this is an EU rule, not a UK one, and why that still matters in the UK

EU Implementing Regulation 2026/1963 requires importers of certain steel and steel-derivative products entering the EU to provide evidence of the country of melt and pour, together with the heat number, from 1 October 2026. The primary evidence is a Mill Test Certificate stating both. Where a certificate cannot be produced or does not contain that information, customs authorities may accept a defined list of alternative documents, invoices, delivery notes, quality certificates, long-term supplier declarations, production records, and similar, as evidence instead, subject to a transitional period: these alternatives can stand alone until 30 September 2027, after which they only supplement a Mill Test Certificate rather than replace one. Missing evidence results in the import being refused, independent of whether a tariff quota is still available.

Northern Ireland continues to follow EU customs rules under the Windsor Framework, so the EU's melt and pour requirement applies to steel moving into Northern Ireland, whether that movement originates in Great Britain or outside the UK entirely. CDS Release 5.3.0.1 is HMRC's system change to support that: it adds the document codes (C131 to C139) and the country-of-melt-and-pour codes (Y376 to Y387, one code per originating country) that a Northern Ireland steel declaration now needs to carry. The codes are appearing in the UK's own declaration system because UK software has to be able to file a compliant Northern Ireland declaration, not because the underlying policy is a UK one.

Why Great Britain is a different answer, for now

HMRC and BIFA guidance on this release are explicit that the EU melt and pour requirement does not change what is required for goods imported directly into Great Britain. The UK government flagged, in its Steel Strategy, that it is exploring its own melt and pour reporting requirement for steel, with further detail expected from the Department for Business and Trade. That is a live policy question worth watching, but it is a separate, not-yet-implemented UK decision. It is not something CDS Release 5.3.0.1 itself switches on for GB imports, and nothing in this release should be read as requiring melt and pour evidence on a steel declaration that moves straight into Great Britain and goes no further.

That distinction is the one most worth getting right this month, because the codes landing in CDS on 22 October make the Northern Ireland requirement visible inside a UK system at the same time as a GB-only requirement is still only under discussion. The two are easy to conflate precisely because they are arriving in the same software release.

Who is actually affected

1. Importers and forwarders moving steel or steel-derivative products into Northern Ireland, whether the goods come from Great Britain or from outside the UK. These declarations need the country of melt and pour and heat number evidence, and from 22 October 2026 the CDS codes to carry that data are in place.
2. Customs agents filing Northern Ireland steel declarations on a client's behalf. The new codes need to be selected correctly, and the underlying evidence, ordinarily a Mill Test Certificate, needs to be collected from the client or their supplier before the declaration can be completed.
3. UK steel importers and brokers watching for a GB equivalent. Nothing is due now, but the UK's own Steel Strategy work means this is a reasonable one to track rather than assume has been ruled out.

What happens if the evidence is missing or wrong

Where the EU melt and pour requirement applies, missing or inadequate evidence results in the import being refused at the point of entry, regardless of whether a relevant tariff quota still has room in it. For a Northern Ireland movement, that means the practical cost of getting this wrong is not a query or a correction cycle after the fact, it is the goods not clearing. The alternative-evidence transitional arrangement running to 30 September 2027 gives some room where a Mill Test Certificate genuinely cannot be obtained, but it is a stopgap, not a reason to defer collecting melt and pour evidence as a routine part of sourcing steel for a Northern Ireland-bound shipment.

What to check this week

1. Confirm whether any of your steel or steel-derivative movements go into Northern Ireland, whether directly or as a leg of a wider GB-to-NI or rest-of-world-to-NI supply chain. If none do, this release does not change what you file today.
2. If they do, confirm you can obtain a Mill Test Certificate, or one of the accepted alternative documents, stating the country of melt and pour and the heat number, before the declaration is due, not after a shipment is already in transit.
3. Ask your declarations software provider whether it has picked up the new C131 to C139 and Y376 to Y387 codes from Appendix 5A, so a Northern Ireland steel declaration can actually carry the evidence once it is in hand.
4. Do not assume a GB-only steel import needs melt and pour evidence because of this release. It does not, today. Track the UK's own Steel Strategy work separately if GB steel imports are a meaningful part of your business.

Frequently Asked Questions

Does CDS Release 5.3.0.1 require melt and pour evidence for steel imported into Great Britain?

No. The release adds document and country codes that support declaring melt and pour origin, but the underlying requirement to provide that evidence comes from an EU regulation that applies to steel moving into Northern Ireland. It does not currently apply to steel imported directly into Great Britain. The UK government has said it is exploring its own melt and pour requirement, but that is a separate policy question, not something this release introduces for GB imports.

What is melt and pour origin, and how is it different from normal customs origin?

Melt and pour origin is the country where steel was first produced in liquid form and cast into its first solid shape. Normal customs origin for tariff and preference purposes usually turns on where goods were last substantially transformed, which can be a different country to where the underlying metal was melted and cast. Melt and pour rules exist to capture that earlier step specifically.

What evidence does a Northern Ireland steel declaration need under this rule?

The primary evidence is a Mill Test Certificate stating the country of melt and pour and the heat number. Where that cannot be produced or lacks the required detail, a defined list of alternative documents, such as invoices, delivery notes, quality certificates, and long-term supplier declarations, may be accepted, as a standalone alternative until 30 September 2027 and as supplementary evidence to a Mill Test Certificate after that date.

What codes does CDS Release 5.3.0.1 add for this, and what else is in the release?

It adds document codes C131 to C139 and country-of-melt-and-pour codes Y376 to Y387 to Appendix 5A. The same release, effective 22 October 2026, also includes additional information codes for Great Britain and Northern Ireland, a TOR01 code validation change, and new measurement unit codes.

What happens if the melt and pour evidence is missing on a declaration that needs it?

Where the EU requirement applies, HMRC and EU guidance indicate the import will be refused at the point of entry if the required evidence of melt and pour country and heat number is missing, independent of whether a relevant tariff quota still has available room.

How Phlo Systems helps

tradePhlo's Declarations module files UK CDS import and export declarations and is kept current against HMRC's Appendix 5A code updates, including the document and country codes introduced in Release 5.3.0.1, so a Northern Ireland steel movement can be declared with the correct melt and pour codes once the supporting evidence is in hand. For customs agents and forwarders filing on a client's behalf, that means less time spent tracking which code list applies to which movement, and more time on the parts of the declaration that need professional judgement. See how tradePhlo handles UK customs declarations.

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Related reading:

• What is the UK Customs Declaration Service (CDS), and how do you submit an import declaration in 2026?
• What does NCTS Phase 6 actually change for UK transit declarations?
• HMRC's CDS report contracts expired 31 March 2026: are you still using TRE?

Saurabh Goyal is the Founder & CEO of Phlo Systems. He spent 12 years building CTRM and ERP systems for global commodity trading houses before founding Phlo in 2016.