UK exporters get extra runway to keep zero‑tariff access into South Korea. HM Treasury has updated the Republic of Korea origin reference document to version 1.3, dated 31 October 2025. The Department for Business and Trade’s reference page lists the document as applying from 31 December 2025, with an ‘entry into force’ noted as 1 January 2026. For traders, read this as the revised rules biting from New Year shipments, with the legal switch at year‑end.

What actually changes is specific and material. An Exchange of Notes signed in Seoul on 24 October 2025 extends two reliefs: EU cumulation of origin and the ability to route goods “through the EU” under the direct transport rule. Both now run until 1 July 2027, or earlier if a modernised UK–Korea FTA takes effect. In practice, EU‑origin materials can keep counting toward UK origin for Korean preferences through mid‑2027, so long as product‑specific rules are still met.

Why this matters is obvious for manufacturers that source components on both sides of the Channel. UKFT warned in October that losing EU cumulation at end‑2025 would pinch sectors like textiles that rely on EU inputs. And when government first extended these provisions in 2023, DBT highlighted expected gains for automotive and food and drink-areas where EU content is common.

A simple automotive example helps. A Midlands driveline maker assembling an e‑axle with German magnets and French sensors can continue to count those EU parts as “originating” when shipping the UK‑made unit to Ulsan, provided the finished good meets the FTA’s product rule and UK processing goes beyond minimal operations. The origin declaration filed by an approved exporter remains the proof Korean customs will expect.

Textiles see the same benefit. A Leeds apparel brand weaving fabric in Italy and cutting and sewing in Yorkshire can still qualify for zero duty into Korea because EU processing is cumulated with UK processing. The commercial upshot is stable landed pricing for Korean buyers who have grown used to tariff‑free UK apparel.

The claiming process is unchanged. DBT guidance confirms preference is claimed using an origin declaration made by an approved exporter, or by any exporter for consignments up to €6,000. Keep commercial evidence that EU inputs are genuinely EU‑origin, ensure your HS code aligns with the rule you’re using, and file the declaration on commercial paperwork.

Routing remains workable via the EU. Government guidance allows consignments to be split in the EU so long as goods stay under customs control and do not clear EU customs. The new Exchange of Notes cements that approach until 1 July 2027; after that date the words “or through the EU” are due to fall away unless a modernised deal kicks in sooner.

The dates to plan around are now clear. Document v1.3 is dated 31 October 2025; the UK instrument applies it from 31 December 2025; and the government page lists 1 January 2026 as the entry‑into‑force marker for traders. The extended EU cumulation and EU transit provisions run to 1 July 2027, or earlier if the upgraded FTA takes effect-so build 2026 shipment schedules on that footing.

For finance teams and lenders underwriting receivables, the operational risk sits with origin evidence. Tighten supplier contracts to require origin documentation for EU inputs, align who holds approved‑exporter status with your Incoterms and billing flows, and reconcile invoice origin statements to the bill of materials. A failed claim can reverse price competitiveness once Korean MFN duty is applied, so this is a margin‑protection exercise as much as a customs task.

What’s next? A broader upgrade of the UK–Korea FTA is in train; the treaty papers published in June 2025 signal a wider refresh ahead. Until then, the amendment agreed in Seoul keeps today’s working model in place and avoids a cliff‑edge for exporters. Use the next 18 months to lock in documentation discipline rather than last‑minute re‑sourcing.