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.

The QuickSMS Filtering Risk Score is a composite index that combines four weighted components: regulatory restriction level (30%), carrier spam enforcement aggressiveness (30%), sender ID policy strictness (25%) and known route quality (15%). Higher scores indicate greater risk of message filtering or non-delivery for A2P senders without local registration or carrier agreements. A score of 0–25 represents a low-friction, open market. 26–50 indicates moderate friction with some carrier filtering. 51–75 indicates high filtering risk requiring route optimisation. 76–100 indicates extreme risk where only locally-registered or direct-carrier routes are viable.

The QuickSMS OTP Deliverability Score estimates the percentage of one-time password messages that successfully reach the end user under optimal routing conditions — i.e. using a compliant sender ID, registered route and carrier-approved message template where applicable. The score is derived from carrier filtering behaviour, route quality benchmarks and registration compliance requirements. Scores above 95% indicate highly reliable OTP delivery. 85–95% indicates acceptable delivery with route sensitivity. Below 85% indicates material delivery risk that should be mitigated with local aggregator partnerships or alternative authentication channels.

The QuickSMS AIT Risk Score measures the prevalence and severity of Artificially Inflated Traffic fraud activity in each market. It is calculated from three factors: frequency of documented AIT incidents on carrier routes (40%), termination rate structure incentivising fraud (35%) and regulatory enforcement effectiveness (25%). Scores above 80 indicate markets where AIT fraud is endemic and aggressive rate-limiting or block-listing of high-risk carriers is strongly recommended. Scores of 60–80 indicate elevated risk requiring monitoring. Below 60 indicates manageable risk with standard fraud controls.

Intelligence is compiled and verified by the QuickSMS team through direct carrier testing, regulatory monitoring and live network observation, cross-referenced against ITU country reports and GSMA guidelines. Each country entry is reviewed against: national telecom regulator published policies, carrier technical documentation, QuickSMS network test results, industry fraud advisories and aggregator partner intelligence. Data is verified and updated with each page release. Where regulatory or carrier data is unavailable or ambiguous, scores are marked as estimates and conservative (higher risk) values are applied.

The filtering severity level is a qualitative classification derived from the Filtering Risk Score and supplementary carrier behaviour data. Low (score 0–25): Open markets with minimal carrier filtering, no mandatory registration. Medium (26–45): Moderate filtering; sender ID registration recommended. High (46–65): Active carrier filtering; registration typically required. Very High (66–80): Aggressive filtering; only registered or direct-carrier routes viable. Extreme (81–100): Near-total filtering of unregistered traffic; local entity or domestic aggregator mandatory.

Registration status reflects whether a country mandates formal pre-registration of sender IDs, message templates or business entities before A2P traffic is accepted by domestic carriers. Allowed: Alphanumeric sender IDs are permitted without registration. Registered: Sender IDs require pre-approval with the regulator or carrier. Restricted: Alphanumeric IDs are permitted only for approved categories (e.g. transactional only). Blocked: Alphanumeric IDs are not supported; numeric or short code routes required. Registration requirements are sourced from national regulator documentation and carrier technical specifications.