Understanding A2P Bypass Fraud: How It Erodes Telecom Revenues and What You Can Do About It

Introduction: Why A2P Messaging Matters

Application-to-Person (A2P) messaging is a rapidly growing source of revenue for mobile operators. Banks send one-time passwords (OTPs), airlines confirm flight bookings, and businesses share promotional messages, all through A2P SMS.

However, fraudsters are exploiting this channel to steal fees. A2P bypass fraud occurs when attackers route legitimate-looking A2P messages through unauthorized or “grey” routes (for example, using illicit SMS gateways or SIM farms) to evade normal interconnect fees.

In effect, these illegitimate paths let fraudsters deliver bulk A2P messages without paying the proper termination charges. For instance, industry analysis estimates that global messaging fraud (including A2P bypass) could cost operators on the order of tens of billions of dollars annually (up to $60 billion of potential losses each year from SMS fraud globally).

What is A2P Bypass Fraud?

A2P (Application-to-Person) messaging is a type of communication that allows businesses to send messages to mobile phones. This can be used for a variety of purposes, such as marketing, customer service, and two-factor authentication. However, A2P messaging is also vulnerable to fraud.

One type of A2P fraud is known as bypass fraud. This occurs when fraudsters send messages through unauthorized channels, bypassing the normal A2P messaging gateways. This allows them to avoid paying the appropriate fees and to send messages that would otherwise be blocked.

A2P Bypass Fraud occurs when messages intended to be billed as high-value A2P traffic are disguised or rerouted to pass as low-cost P2P (Person-to-Person) messages, or worse, completely avoid billing systems.

Example:

“A financial institution sends an OTP via a bulk messaging platform. Instead of using a legitimate A2P route, the message is funneled through a SIM farm or a grey route, making it look like a personal message. The operator loses revenue, and the message may suffer delays or quality issues.”

How A2P Bypass Fraud Works

Fraudsters and rogue aggregators may use the following tactics:

• Grey-route SMS: Fraudsters redirect messages through unofficial carrier links that bypass regulated interconnect agreements and don't comply with local termination rules. Grey routes are an insidious form of bypass fraud where A2P traffic avoids legitimate interconnect agreements. Studies show grey routing is the largest bypass vector, it affecting over 50% of mobile operators. In practice, grey-route A2P messaging can occur via international SS7 links or re-purposed P2P routes.
• SIM farms/SIM boxes: Attackers use bulk consumer SIMs to route messages, allowing messages to be billed at P2P rates rather than the premium A2P rates. These are often deployed in regions with weak enforcement.
  They usually deploy hundreds or thousands of SIM cards on locally-registered phones to send A2P SMS as if they were ordinary person-to-person texts. SIM box schemes have been observed to account for 10–12% of traffic on some networks before intervention. Extensive SIM-farm activity can funnel large A2P volumes out of the operator’s legitimate channels.
• Aggregator/MVNO bypass: Rogue aggregators or MVNOs without proper termination agreements can inject A2P traffic into operator networks via open links. For example, an operator may receive A2P traffic from a domestic competitor’s network without paying termination fees.
• Domestic interconnect abuse: In some markets, competitors may send A2P traffic to each other at unfairly low domestic rates instead of routing through international A2P channels, again evading fees.
• Sender ID spoofing and bulk SMS spam: Attackers may spoof legitimate brands or subscriber numbers in A2P messages, and flood subscribers with unsolicited SMS. Though not a bypass per se, these schemes often accompany bypass fraud, all contributing to messaging spam and regulatory risk.

Why Is A2P Bypass Fraud a Major Threat?

A2P bypass fraud can have a number of negative impacts on businesses and consumers. Businesses can lose revenue as a result of fraudsters sending messages without paying the appropriate fees. Consumers can also be harmed by receiving spam messages, phishing messages, or messages that deliver malware.

In addition, A2P bypass fraud can damage the reputation of businesses and harm their relationships with customers.

• Revenue Loss for Carriers & Enterprises
  • Mobile network operators (MNOs) lose billions annually due to unpaid A2P fees. Each SMS sent over an illegitimate route skips the agreed fees, directly reducing operator revenue. As one source notes, the booming A2P market (projected at tens of billions of dollars) can only reach its potential if operators plug this leakage
  • Enterprises may unknowingly use fraudulent routes, leading to higher costs when carriers detect and block suspicious traffic.
• Security & Compliance Risks
• Fraudulent routes lack proper security, making them vulnerable to phishing, spoofing, and malware distribution.
• Unauthorized bypass can lead to network congestion and security vulnerabilities, such as compromising SS7 networks, and may even conflict with regulatory standards. In summary, fraudsters exploiting A2P bypass schemes (not only restrict operator revenue streams but also expose customers to increased levels of spam).
• Regulatory fines may apply if businesses unknowingly send messages via illegal channels.
• Degraded Customer Trust
• Spam or phishing SMS sent via bypass channels degrade user experience and undermine confidence in SMS
• Legitimate OTPs or alerts may be delayed or blocked due to carrier filtering.

Financial Impact of A2P Bypass Fraud

The financial consequences of A2P Bypass Fraud are substantial. According to a recent GSMA report, revenue losses due to grey route and bypass fraud account for between 10% to 15% of A2P messaging revenues in some emerging markets. This statistic highlights how fraudsters can siphon off significant revenue, especially in regions where mobile money and digital transactions are rapidly growing.

Moreover, operators not only face reduced income but may also incur additional costs associated with investigating and mitigating these fraud incidents. The ITU has also underlined that the surge in digital transactions, partly accelerated by the pandemic, has increased the vulnerability of messaging ecosystems, making robust fraud prevention measures more essential than ever.

Key Indicators of A2P Bypass Fraud

Operators must monitor several key performance indicators (KPIs) to detect signs of A2P bypass fraud. Some of the most important indicators include:

• Revenue Leakage: A significant drop in revenue per transaction compared to industry benchmarks.
• Traffic Anomalies: Unusual spikes in SMS volumes coming from specific, low-cost routes or SIM banks.
• Delivery Delays: Increased latency or failed message deliveries that may indicate routing issues.
• Discrepancies in Billing: Mismatches between expected A2P charges and actual collected revenue.

These indicators provide a solid foundation for assessing the extent of A2P Bypass Fraud and guiding subsequent remediation efforts.

• High SMS volume from SIMs with no voice/data usage
• Consistent international message patterns from local SIMs
• Unusual delivery timing and quality patterns
• Multiple SIMs activated on the same device/IP

How to Prevent A2P Bypass Fraud

Operators must adopt multi-pronged defenses to detect and prevent A2P bypass. Key strategies include:

• Full traffic visibility: Capture detailed signaling and message routing data for all incoming A2P SMS. Real-time dashboards and analytics can flag anomalies (sudden volume spikes, unusual origin networks, etc.).

• Leverage AI and Machine Learning Machine-learning models can ingest historical and real-time CDRs to learn normal A2P behavior and rapidly identify deviations and subtle anomalies indicative of bypass fraud.

• SMS Firewall and Routing Controls: A specialized SMS firewall inspects every inbound and outbound message’s source, destination, and routing path. Properly configured, the firewall blocks unauthorized or suspicious routes.The ideal solution to combat grey route messaging is an SMS firewall, which guarantees that “there is no A2P bypass…or any other illegal bypass.” Modern firewalls have the capability to:

  • Automatically drop messages from known grey or black routes
  • Prevent spoofed sender IDs
  • Enforce operator-defined policies, such as allowing only approved international A2P gateways

  By filtering out fraudulent traffic at the network edge, operators can eliminate bypass traffic before it impacts their revenue.

• Fraud monitoring and enrichment: Beyond simple rules, employ anomaly detection (e.g. threshold limits, behavioral profiles). For instance, correlating SMS volume changes with network topology or time-of-day can highlight rogue activity. Analytics can also integrate external intelligence, known fraudulent SMS origins, blacklisted IDs, or subscriber complaints, to improve accuracy.

• Partnerships and pricing policies: Close loopholes with commercial and regulatory measures. Operators should negotiate proper A2P interconnect agreements and implement competitive, use-case-based pricing that disincentivizes grey routing.

• Regulatory Reporting: Work with regulators and Align with local regulatory frameworks and report suspicious activities to enforcement agencies. Also collaborating with other carriers to blacklist known bypass sources (or block illegal routes at origin) helps too. Collaboration through industry forums (e.g. GSMA SMS Firewall working groups) can also yield shared threat intelligence on grey-route hubs.

• Enhance Customer and Employee Awareness: Educate customers on recognizing fraudulent messages and train staff to identify potential fraud indicators quickly.

• Educate Marketing & Sales Teams: Ensure your marketing teams understand the risks of unauthorized SMS providers and encourage the use of approved A2P routes for campaigns.

Webinar

To explore more about A2P bypass mitigation techniques, watch our webinar “Protecting A2P SMS Revenues: How to Detect and Prevent Bypass Fraud with Real-Time Data”. In that session, our expert discuss evolving bypass trends and demonstrate how Synaptique’s platform applies advanced analytics to uncover illicit A2P routes before they hurt your bottom line.

Final Thoughts: It's Time to Take Control

In summary, A2P bypass fraud is a growing silent revenue killer for telecom operators that undercut legitimate SMS termination. The cost can be enormous, A report by Mobilesquared warned that if just 25% of all global SMS traffic ran via grey routes by 2024, it would amount to about $37.1 billion in collective losses. Left unchecked, bypass schemes also wear away user trust and strain networks.

Fortunately, modern telecom analytics and AI can combat these schemes in real time. By combining full visibility (via real-time CDR collection and dashboards) with intelligent filtering (SMS firewalls and ML models), operators can detect A2P anomalies as they happen and block fraudulent SMS flows before damage accrues

Without proper monitoring and prevention, millions can be lost annually. The solution lies in a combination of technology, expertise, and vigilance.