Chile’s Undersecretariat of Telecommunications (SUBTEL) published the anti‑fraud special circular Oficio Circular N°956/2025 in January 2026. It reaffirms requirements from OC‑863 and targets Sender‑ID spoofing and phishing SMS. It imposes binding rules for A2P sender identifiers, operator‑gateway interception, SMPP interface privileges and communication‑log retention, applied jointly with the 600/809 number‑range governance rules.
The circular fully prohibits alphabet‑based and custom‑brand‑alias sender IDs. Bulk A2P SMS can only be transmitted through SUBTEL‑allocated compliant numeric number ranges 600 and 809, eliminating technical conditions for impersonating enterprises and public institutions at source. The four carriers Entel, Movistar, Claro and WOM are ordered to implement real‑time gateway interception, blocking inbound traffic with foreign alphanumeric sender‑IDs and fake messages pretending to be financial or governmental bodies.
A 30‑day remediation window is granted. Within this timeframe operators must disable custom sender‑ID rewriting capabilities across all wholesale SMPP interfaces; A2P service‑providers may no longer alter sender identifiers on their own. Mandatorily, all A2P delivery records and delivery‑receipt logs shall be preserved within Chile for 12 months and made available for regulatory audits upon request.
As a supplementary regulatory instrument to Circular 575/2025 on number‑range management, this circular covers all A2P aggregators, wholesale channel providers and SP‑service‑providers connected to Chilean mobile networks. Infringing parties face penalties under the Basic Telecommunications Act Ley 18.168. In serious cases operators may disconnect SMPP peering sessions directly. Overseas cloud platforms remain barred from direct operator connections; all traffic must be routed through locally‑licensed domestic aggregators.
