Japan 433 MHz TPMS/RKE Certification: Key Changes and Compliance Timeline

Japan's Ministry of Internal Affairs and Communications (MIC) has formally amended the Ordinance for Enforcement of the Radio Act to permit 433 MHz operation for Tire Pressure Monitoring Systems (TPMS) and Remote Keyless Entry (RKE) devices. This regulatory update — one of the most significant in Japan's automotive wireless space in decades — aligns Japan with global frequency standards and removes longstanding market barriers for international manufacturers. Full entry into force is proposed for June 2026.

Background: Why Japan Is Moving from 315 MHz to 433 MHz

For decades, Japan required TPMS and RKE systems to operate within the 315 MHz band as license-exempt 'specified low-power' radio stations under the Radio Act. While functional domestically, this frequency diverged significantly from international practice — creating a Japan-specific certification burden that complicated market access for global manufacturers.

The new Japan 433 MHz TPMS RKE certification framework brings Japan in line with the globally accepted 433.05–434.79 MHz band, already the standard across Europe, the Americas, and much of Asia. Japan's alignment reflects three key strategic drivers:

•        Global harmonization: Eliminating Japan-specific frequency requirements reduces Japan 433 MHz TPMS RKE certification complexity for manufacturers supplying multiple markets simultaneously.

•        Improved technical performance: The 433 MHz UHF band offers excellent penetration through physical obstacles with low power consumption — ideal for TPMS sensors embedded within tire assemblies.

•        Regulatory modernization: The MIC's ongoing reform agenda reduces divergences between Japan's domestic radio standards and international norms, making Japan 433 MHz TPMS RKE certification more predictable for global manufacturers.

Regulatory Timeline for Japan 433 MHz TPMS/RKE Certification

The following timeline summarizes all key regulatory milestones from the initial public consultation through to the proposed entry into force:

Date	Milestone
Sep–Oct 2024	MIC public comment period on proposed 433 MHz technical conditions
October 2024	WTO TBT Notification G/TBT/N/JPN/840 issued
February 27, 2025	Ordinance No. 5 enacted — 433 MHz officially opened for TPMS and RKE
January 22, 2026	Land Radio Communications Committee 97th meeting — draft report compiled
Jan 28 – Feb 26, 2026	Public consultation period opened
February 13, 2026	WTO TBT Notification G/TBT/N/JPN/899 issued
Until April 14, 2026	International stakeholder comment period (enquiry@mofa.go.jp)
June 2026 (proposed)	Entry into force — 433 MHz TPMS/RKE regulation fully effective

Key Technical Changes Under the Radio Act Amendment

The MIC's amendment introduces specific technical conditions that manufacturers must incorporate into product design and Japan 433 MHz TPMS RKE certification submissions. Understanding these requirements is essential before engaging a test laboratory.

1. Expanded Frequency Band

The permitted operating frequency for TPMS and RKE devices is formally expanded to 433.05–434.79 MHz. Specifically, the 433.795–434.045 MHz sub-range is designated as the primary Specified Low Power Radio Station class for these applications.

2. Transmission Duty Cycle Restrictions

New duty cycle limits apply to manage spectrum efficiency and reduce interference risk:

•        Total transmission time per hour must not exceed 360 seconds.

•        In periodic transmission mode, radio signals must stop within 1 second after each emission.

•        The minimum pause between transmissions is 1 millisecond.

3. Removal of Enclosure Requirements

Previous requirements imposed on the physical equipment enclosure for TPMS and RKE devices will be eliminated under the revised Regulation for Radio Equipment and the relevant Public Notice. This simplification reduces design constraints for manufacturers.

4. Interference Protections Retained

Protections to prevent interference with other services — most notably the amateur radio service — remain fully in force. These include maximum permitted transmission power, channel bandwidth limits, and environment-specific operating conditions.

What This Means for Japan 433 MHz TPMS/RKE Certification

This regulatory update has direct implications for any manufacturer developing, importing, or distributing TPMS or RKE systems for the Japanese market. Understanding these impacts is essential for maintaining uninterrupted market access.

MIC Certification Requirements

Devices operating in the 433 MHz band will require MIC type certification under the new technical framework. Existing 315 MHz certifications do not automatically transfer. Manufacturers should assess whether their current approvals remain valid and begin preparing updated technical files.

Product Design Implications

The removal of enclosure requirements offers new design flexibility, but the duty cycle restrictions impose important constraints on transmission architecture. Firmware and hardware teams should evaluate these limits early in the development cycle rather than retrofitting compliance at the certification stage.

Market Access Risk

After the June 2026 entry into force, devices that do not comply with the new Japan 433 MHz TPMS RKE certification requirements — or that continue to operate solely on 315 MHz without a valid transition approval — may face distribution restrictions in Japan. Proactive planning is the most effective way to protect market access.

Certification Impact Summary

The table below summarizes the key certification impacts and required actions for manufacturers:

Area	Impact	Action Required
Type Approval	New MIC certification needed for 433 MHz devices	Prepare technical documentation
Product Design	Enclosure requirements eliminated; duty cycle limits apply	Review and update device specs
Frequency Change	315 MHz devices may need re-evaluation	Assess existing approvals
Market Access	Devices must comply before June 2026 entry into force	Plan certification timeline now
Testing	New technical conditions for 433.05–434.79 MHz range	Engage accredited test lab

Required Actions Before June 2026

Manufacturers and importers of TPMS and RKE systems for Japan should take the following steps:

•        Review product specifications to confirm compatibility with the 433.05–434.79 MHz frequency range and new duty cycle requirements.

•        Assess all existing 315 MHz MIC approvals to determine whether they remain valid or require transition under the new framework.

•        Engage an accredited test laboratory to begin planning test campaigns against the new technical conditions.

•        Prepare MIC certification documentation, including technical files, test reports, and declarations of conformity.

•        Monitor WTO TBT notifications G/TBT/N/JPN/840 and G/TBT/N/JPN/899 for finalized implementation rules.

•        Submit stakeholder comments via enquiry@mofa.go.jp before April 14, 2026, if applicable to your organization.

•        Build June 2026 into project timelines as a hard compliance deadline to avoid market disruption.

Official Government Sources

All information in this article is based on the following primary regulatory sources:

•        Ministry of Internal Affairs and Communications (MIC): www.soumu.go.jp

•        WTO TBT Notification G/TBT/N/JPN/840 — October 2024

•        WTO TBT Notification G/TBT/N/JPN/899 — February 13, 2026

•        Ordinance No. 5 — February 27, 2025 (Ordinance for Enforcement of the Radio Act)

•        Land Radio Communications Committee Report — Inquiry No. 2009, 97th Meeting, January 22, 2026