Japan

Japan mandated eCTD v4.0 from 1 April 2026, making it the first major ICH region to reach the v4.0 mandatory phase (under MHLW Notification 0218-4, 18 Feb 2022; the transition period for the former eCTD format ran to 31 March 2026). The mandate applies to 'new applications' filed on or after that date, covering pharmaceuticals, medical devices and in vitro diagnostics; dossiers already started in v3.2.2 before that date continue to be handled in v3.2.2 for their full lifecycle, with no retroactive conversion required. PMDA's v4.0 domestic toolchain is complete: the Domestic Implementation Package v1.6.0.3 (updated 3 June 2026, including JP IG v1.6.0, JP CV, OID and the check-item list) and the v4.0 Verification Tool (3 June 2026) are both downloadable.

The cutover is keyed to the application's start date, not the submission date: for dossiers already begun in v3.2.2 before 1 April 2026, supplements and variations continue in v3.2.2 until PMDA says otherwise; once a dossier is re-baselined in v4.0, every subsequent submission unit must be v4.0 (the two are not backward compatible). eCTD v4.0 is built on the HL7 RPS message model — documents are located by controlled vocabulary and metadata (Context of Use / Keyword), so publishing work must move upstream to authoring. Regional differences are concentrated in Module 1 and the JP CV (Japan-controlled vocabulary); Modules 2–5 follow the ICH specification.

Japan's mandatory baseline for years. From 1 April 2026 PMDA no longer accepts v3.2.2 for 'new applications', so for new filings the version is superseded by eCTD v4.0; however, dossiers already started in v3.2.2 before that date continue to be handled in v3.2.2 for their subsequent sequences (supplements, variations, etc.), with no conversion required. PMDA still maintains the v3.2.2 Validation Tool (last updated 17 September 2025), so ongoing-lifecycle sequences can keep self-validating and submitting.

Do not treat v3.2.2 as 'shut down': for dossiers that existed before 1 April 2026 it remains a valid lifecycle baseline until that dossier is re-baselined in v4.0 or PMDA notifies otherwise. New projects and new applications must go straight to v4.0 — do not set up a v3.2.2 publishing chain for them.