Summary

  • A sender, intended recipient or other affected person can challenge a mobile-message block, including through their own provider when they do not know who stopped it.
  • Ofcom declined to require notice of every automated block, so providers must proactively find false positives rather than count only the challenges that arrive.

A text that fails to arrive leaves an awkward gap in the evidence: the recipient may not know anything was sent, and the sender may not know which network made the decision. Ofcom’s July 2026 final rules address that gap with two linked controls. They give affected people a challenge and appeal route, and require certain blocking providers to monitor errors even when nobody complains. The design matters because the first control depends on someone seeing a problem; the second must account for messages that disappear without a visible failure.

Under General Condition C9.17, a person affected by a number or message block can challenge it. Ofcom expressly includes senders and intended recipients, and allows a challenge to go to the person’s own provider or the provider that applied the block. That distinction matters in a multi-network delivery path: the person trying to resolve a missing message may have no reliable way to identify the blocking operator. Ofcom says the customer’s provider must take reasonable steps to resolve the challenge rather than pass the person from one company to another.

The process is a targeted review, with an appeal, and can lead to unblocking where that is appropriate and possible. It is not a guarantee that every legitimate message will be delivered, or that a message missed during review will be resent. Nor does the dedicated challenge automatically become a standard complaint with a specific right to alternative dispute resolution. Ofcom treats those as distinct procedures.

The other half of the design is what providers must do when nobody asks for a review. Ofcom did not adopt its proposal to notify senders whenever specified messages are blocked automatically. It reasoned that a notice could reveal which controls stopped a scammer and help that person adjust. But that choice makes silent errors harder for users to discover. GC C9.26 therefore requires providers within the relevant blocking scope to maintain effective systems for identifying and monitoring false positives and to act promptly when they find them.

Ofcom says a provider should not rely mainly on appeals, queries or complaints to estimate error rates: people may never learn that a message was blocked. It expects proactive checks, using automated tools, human review or periodic examination of blocked messages and traffic patterns. Responses to Ofcom’s May 2026 information requests showed uneven starting points. Some providers described manual checks at least daily; others appeared to have no proactive process and learned of errors through complaints. Those responses show a monitoring gap, not a comparable national accuracy rate.

The direct monitoring duty follows the defined blocking roles; Ofcom’s guidance excludes lower-tier aggregators from C9.26 itself. Providers must also make their challenge policy accessible and explain to users when messages may be blocked and how to contest a decision, even though each automated block need not generate a notice.

The provider guidance adds an evidence-retention layer: communications about challenges should be kept for 12 months after a case concludes, while false-positive incidents and the actions taken should be recorded for two years. The rules arrive on separate clocks. The P2P provisions take effect on 18 January 2027; the A2P provisions follow on 15 July 2027. The distinction gives operators, aggregators and business senders time to map who blocks, who receives a challenge, and which team can correct a recurring filter error.

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