Summary

  • The special transition for existing Global Title authorizations tied to MVNO and in-vehicle migrations ended on 22 October 2026.
  • The remaining route is narrow: a number allocator may authorize a same-group entity or a service supplier using the number exclusively for that service.

Some phone numbers get to do two jobs. A subscriber sees one on a handset; a mobile network may also use it inside SS7 as a Global Title, a signalling address that helps route network messages. The public never sees that second job. Ofcom’s rulebook now gives it a move-out date.

The 18-month transition for two specific existing arrangements expired on 22 October 2026. Ofcom set that longer window because the changes involved significant network-functionality challenges. The date is easy to miss because the broad restrictions started earlier: on 22 April 2025, Ofcom barred new Global Title leasing and new GTs created from sub-allocated numbers. The later dates covered legacy arrangements already in place.

The current National Telephone Numbering Plan assigns the control point to the number. Under B3.8.1, only the person to whom Ofcom allocated a telephone number may create or use a Global Title from it. Under B3.8.2, that allocator cannot authorize another party to use the number as a GT unless the party belongs to the same corporate group or supplies a service to the allocator and uses the number exclusively for that service. “We have always done it this way” did not make a third exception.

B3.8.3 gave existing users time to move. The first transition ended on 22 April 2026. The extra six months applied only to two journeys defined in the Plan. An MVNO Migration Journey covered an MVNO that was using Global Titles for core-network elements on 22 April 2025 and was preparing to transfer those services to another mobile provider’s facilities and core. The in-vehicle journey covered an MVNO serving devices embedded in vehicles that planned to provide those services using its own Global Titles for its core network.

That distinction matters. One journey shifts service to another provider’s core; the other prepares an MVNO to use its own signalling addresses for connected vehicles. Both needed network changes, so Ofcom gave them extra time. The definition ties the extension to what the MVNO was doing on 22 April 2025 and what it was preparing to do next. It was a migration runway, not an industry-wide parking permit.

The surviving B3.8.2 exceptions are structural, not calendar extensions. A number holder can authorize use inside its corporate group, or let a service supplier use the number only to provide that service. The test now sits in the authorization and the actual use: who allocated the number, who uses the GT, what service is supplied, and whether the number is kept exclusive to it.

Ofcom’s public statement and the current Plan specify the deadline. They do not publish a post-deadline register of migrated Global Titles, remaining authorizations or network cutovers. So the rule’s next chapter is operational: number holders need an inventory that joins each telephone number to its GT, user, contractual basis and migration state. The signalling address has been told to move; the public ledger has not yet shown who packed.

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