Digital Agency Revises Electronic Signature Standards for My Number Cards

The Digital Agency promulgated Digital Agency Ordinance No. 21 and Digital Agency Notice No. 38 on October 15, 2026, which revise the measures for electronic signatures and alteration verification pertaining to electromagnetic records substituting for cards of the Individual Number Card (My Number Card). Both come into effect on the date of promulgation. They were signed by Prime Minister Sanae Takaichi and Minister for Internal Affairs and Communications Hiayuki Fujii.

Restructuring the Signature Method for Card-Substituting Records Under the Number Utilization Act

The framework for the revision consists of the Act on the Use of Numbers to Identify Specific Individuals in Administrative Procedures (Act No. 27 of 2013; hereinafter the Number Utilization Act), and its subordinate norms: the Ministerial Ordinance on Individual Number Cards, etc. (MIC Ordinance No. 85 of 2014) and the Technical Standards Concerning Individual Number Cards, etc. (MIC Notice No. 314 of 2015). These measures reorganize the correspondence between signature codes and verification codes used during the issuance and transmission of electromagnetic records substituting for cards.

Digital Agency Ordinance No. 21 is an order partially amending the Ministerial Ordinance on Individual Number Cards, etc. The main pillars of the revision are as follows:

• The reference to electronic signatures in Article 39-5, Paragraph 5 was limited to “Paragraph 5, Item 1,” and a new provision corresponding to Item 2 of the same paragraph was established as Paragraph 6.
• The scope of Article 39-25 (measures to confirm that transmission was performed by the user) was changed from “card-substituting record items” to “electromagnetic records pertaining to card-substituting record items” and card-substituting record random codes.
• Article 39-26 (measures to confirm that no alteration has occurred) was restructured into two items, requiring that the electronic signature in Paragraph 6 be verified with a specific card-substituting electromagnetic record issuer signature verification code, and the electronic signature in Paragraph 5 be verified with a card-substituting electromagnetic record issuer signature verification code.

New Item for Specific Signature Codes Added to Technical Standards

Digital Agency Notice No. 38 concerns the partial amendment of the Technical Standards Concerning Individual Number Cards, etc. In the section “Issuance, etc. of Card-Substituting Electromagnetic Records,” a new item was established for electronic signatures performed using a specific card-substituting electromagnetic record issuer signature code, and the period determined by the competent minister under Article 39-5, Paragraph 6 of the Ministerial Ordinance was defined as the period in Section 3(4) of said standards. It is explicitly stated that this is a new addition, as there were no corresponding provisions in the column prior to the revision.

Effective Date of Promulgation and Transitional Measures for Existing Certified Programs

The supplementary provisions of the Order establish a transitional measure whereby providers of transmission programs for card-alternative electromagnetic records, who are currently certified under the standards based on Article 18-3, Paragraph 1, Item 4 of the former Number Utilization Act at the time of enforcement, shall be deemed to be certified under the standards based on the same item after the amendment. The supplementary provisions of the Notification also stipulate enforcement from the date of promulgation.

The impact is broad. For My Number Card users, the legal basis for the procedures to verify the authenticity and non-alterability of card-alternative electromagnetic records will change. Related system operators providing transmission programs for card-alternative electromagnetic records must reflect the correspondence between signature codes and verification codes, as well as the reinterpretation of certification standards, in their own implementations.

Sources

• Digital Agency Order No. 21 (Order Partially Amending the Order Concerning the Individual Number, Individual Number Card, and Provision of Specific Personal Information as Prescribed in the Act on the Use of Numbers to Identify Specific Individuals in Administrative Procedures), promulgated October 15, 2026, Official Gazette (October 15, 2026).
• Digital Agency Notification No. 38 (Matter Partially Amending the Technical Standards Concerning Individual Number Cards, etc.), promulgated October 15, 2026, Official Gazette (October 15, 2026).