Global SMS Filtering & Deliverability Index

SMS delivery rates vary significantly across markets due to the layered relationship between national telecom regulators, mobile network operators and the intermediary aggregators that route A2P traffic. Each country operates its own regulatory framework governing what constitutes compliant commercial messaging, how sender identities must be declared, and what categories of content are subject to filtering. In some jurisdictions — such as India, the United States and Vietnam — formal pre-registration of sender IDs and message templates is mandated before any A2P traffic is accepted by domestic carriers. In others, filtering decisions are made unilaterally at the carrier level with no centralised registry or appeal mechanism.

Carrier-level spam filtering represents one of the most variable factors in global SMS deliverability. Mobile network operators apply filtering based on content heuristics, sender reputation, routing origin and traffic volume patterns. Carriers in high-filtering markets such as Germany, China and the Philippines operate deep content inspection pipelines that block messages containing specific keywords, originate from unregistered sender IDs or arrive via grey routes. These filtering behaviours are not always documented publicly and can change without notice, making real-time network intelligence essential for any operator running high-volume A2P messaging infrastructure.

Sender ID policy — whether alphanumeric sender IDs are permitted, require registration or are blocked entirely — is a primary compliance variable for enterprise messaging programmes. Markets that block alphanumeric IDs require senders to use numeric long codes, short codes or locally registered identifiers. Failure to comply typically results in silent message drops rather than delivery failure reports, masking systemic deliverability problems in analytics pipelines. Registration requirements in markets such as Saudi Arabia, South Korea and the UAE involve formal documentation, approval timelines of days to months, and in some cases the establishment of a local legal entity.

The operational impact is most acute for time-sensitive A2P traffic — OTP authentication, transaction alerts, account notifications and service verification — where delivery failure directly affects user experience and security posture. Enterprises across multiple markets must account for per-country registration obligations, carrier-specific routing preferences, and the growing risk of AIT (Artificially Inflated Traffic) fraud, where compromised verification flows are exploited to generate artificial traffic to premium-rate numbers. This dataset documents filtering behaviour, registration requirements and fraud risk to support routing decisions and compliance planning.