MIC Defines Mobile Network Fixed-Line Telephony to Expand Identity Verification

The Ministry of Internal Affairs and Communications (MIC) promulgated MIC Notice No. 386, which amends the Telecommunications Numbering Plan (MIC Notice No. 6 of 2019), and MIC Ministerial Ordinance No. 120, which amends the Enforcement Regulations of the Telecommunications Business Act (Ministry of Posts and Telecommunications Ordinance No. 25 of 1985), etc., in the Official Gazette (Extra Edition) dated October 22, 2026. Both the ministerial ordinance and the notice newly define “mobile network fixed-line telephony” and incorporate it into regulations such as the verification of end-users at the time of contracting for call forwarding services. The enforcement date of the notice is November 1, 2026, and it was signed by Minister for Internal Affairs and Communications, Hayayuki Fujii.

The legal basis for the amendment is Article 7, Item 1; Article 10, Paragraph 1, Item 3(a); Article 41; Article 42; and Article 176-2 of the Telecommunications Business Act (Act No. 86 of 1984), as well as the proviso of Article 2, Paragraph 5 of the Act on Nippon Telegraph and Telephone Corporation, etc. (Act No. 85 of 1984). The change to the numbering plan is based on Article 50, Paragraph 2 of the same Act. Additionally, MIC Notice No. 387 amended Ministry of Posts and Telecommunications Notice No. 228 of 1985, which specifies the details of the Regulations for Telecommunications Facilities for Business Use (Ministry of Posts and Telecommunications Ordinance No. 30 of 1985), establishing new quality standards for mobile network fixed-line telephony equipment.

New Definition of Mobile Network Fixed-Line Telephony Added to General Provisions of the Numbering Plan

Notice No. 386 added a new definition for mobile network fixed-line telephony as item “f” in Section 1 (General Provisions), Subsection 1 (Definitions) of the Numbering Plan. The definition is stated as “mobile network fixed-line telephony as prescribed in Article 14, Item 5 of the Enforcement Regulations of the Telecommunications Business Act,” creating a structure that refers to the provisions of the ministerial ordinance.

Ministerial Ordinance No. 120 added Item 5 to Article 14 (Scope of Type 1 Basic Telecommunications Services) of the Enforcement Regulations, positioning mobile network fixed-line telephony within the scope of Type 1 Basic Telecommunications Services. Accordingly, Article 4, Paragraph 2 of the same ordinance was amended to target “Article 14, Items 4 and 5,” and Article 4, Paragraph 3, Item 1 was amended to “Article 14, Item 1 and Items 3 through 5.”

Mobile Network Fixed-Line Telephony Added to Terms of Use for Call Forwarding Services

Notice No. 386 amended Item 4 (Call Forwarding Services = cases where a fixed-line telephone number is used as a user equipment identification number in originating or terminating call forwarding) among the conditions of use pertaining to fixed-line telephone numbers (0ABCDEFGHJ) in Section 3 (Matters Concerning User Equipment Identification Numbers) of the Numbering Plan.

• Explicitly specified fixed-line telephones over mobile networks in addition to wireless fixed-line telephones as targets to be excluded from identification by fixed-line telephone numbers.
• Required providers of telephone forwarding services to verify the identity of the end-user using the method specified in Appended Table 4 upon conclusion of a contract.
• The identity verification items to be confirmed are: name, address, and date of birth for natural persons; and name and the location of the head office or principal office for corporations.

Quality Standards and Preparatory Actions Prior to Enforcement

Public Notice No. 387 established the comprehensive quality standards for mutual interconnection between terminal equipment, etc., connected to equipment for fixed-line telephones over mobile networks, based on Article 35-26 of the revised Regulations for Telecommunications Facilities for Business Use.

• The POLQA value of the ITU-T P.863 recommendation must exceed 3.1, and the average delay of the G.114 recommendation must be less than 400 milliseconds.
• As an alternative standard, the POLQA value must exceed 3.6, and the average delay must be less than 500 milliseconds.
• For both, the condition is that the probability of calculating said values must be 0.95 or higher.

The supplementary provisions of Public Notice No. 386 permitted preparatory actions, allowing for the creation of a telecommunications number usage plan that conforms to the new plan and the application for certification under Article 50-2, Paragraph 1 of the Act, even before the date of enforcement. For plans that have already received certification, applications for certification of changes to conform to the new plan are possible before the enforcement date, and the Minister for Internal Affairs and Communications may grant certification or certification of changes before the enforcement date. Public Notice No. 387 also states that notifications based on Article 3, Paragraph 2 of the supplementary provisions of the Ministerial Ordinance may be submitted before the enforcement date in accordance with the revised provisions.

Practical Impact on Carriers and Fixed-Line Telephone Users

This revision explicitly addresses services that provide fixed-line telephone numbers via mobile networks across three layers: the numbering plan, the enforcement regulations, and the equipment regulations. Telecommunications carriers will be required to apply for certification of numbering usage plans, comply with quality standards, and establish identity verification procedures for telephone forwarding service contracts. For fixed-line telephone users, the scope of required identification documents upon contracting for forwarding services will change. Enforcement is set for November 1, 2026, and preparatory actions are already permitted.

Sources

• Official Gazette (Extra Edition) October 22, 2026, MIC Ordinance No. 120 “Ministerial Ordinance to Partially Amend the Enforcement Regulations of the Telecommunications Business Act, etc.” (Minister for Internal Affairs and Communications, Hayayuki Fujii)
• MIC Public Notice No. 386 “Matter Concerning the Partial Amendment of the Telecommunications Numbering Plan (MIC Public Notice No. 6 of 2019),” and its supplementary provisions (Enforcement Date/Preparatory Actions)
• MIC Public Notice No. 387 “Matter Concerning the Partial Amendment of Ministry of Posts and Telecommunications Public Notice No. 228 of 1985,” and its supplementary provisions