Overview
Mobile carriers and industry guidelines (such as CTIA standards) restrict certain types of messaging traffic across the United States and Canada.
These restrictions apply to all major messaging number types, including:
10DLC (long code)
Toll-Free numbers
Short Codes
Sending messages that fall into prohibited categories can lead to carrier filtering, increased error rates, or suspension of messaging capabilities.
This article outlines message types that are not supported on Telnyx messaging services to help you stay compliant and maintain deliverability.
Prohibited Message Categories
The following message categories are not permitted across US and Canada messaging channels.
Illegal Products and Substances
Messages promoting or facilitating the sale of illegal goods are not allowed, including:
Controlled or prescription drugs without proper authorization
Substances that are not legally approved for sale
Unregulated or prohibited supplements
These restrictions apply regardless of business licensing status.
Gambling and Betting
Messaging related to gambling is generally not supported, including:
Online casinos or gambling platforms
Sports betting or wagering services
Betting tips or odds promotion
Some exceptions may exist for approved short code programs, but these require prior carrier approval.
SHAFT Categories
Carriers commonly restrict messaging tied to the following categories:
Sex: Adult content or services
Hate: Hate speech or discriminatory content
Alcohol: Subject to regional and carrier-specific rules
Firearms: Weapons and related products
Tobacco: Including vape and e-cigarette products
Important notes:
Messaging related to firearms, tobacco, or vaping products is not permitted across standard messaging channels.
Alcohol-related messaging may be allowed in certain cases in the US with appropriate age verification and compliance controls, but policies vary by carrier.
Age-Restricted Content (Canada)
Canadian carriers enforce stricter rules for age-sensitive content:
Content intended for restricted audiences must not be sent without explicit approval
Additional registration or exemptions may be required before sending
Deceptive or High-Risk Content
Messages that could be considered misleading, abusive, or fraudulent are prohibited. This includes:
Phishing or impersonation attempts
Misleading financial offers or “guaranteed” returns
Lead generation practices that obscure intent
Any content designed to manipulate or deceive recipients
Restricted Business Models
Certain business types are not supported for messaging, even if individual messages appear compliant. These may include:
Businesses operating primarily in prohibited verticals (e.g., gambling or adult services)
Use cases attempting to evade carrier or regulatory safeguards
Carriers evaluate both message content and overall use case when determining compliance.
Additional Compliance Considerations
Links and URLs
Avoid using generic or public URL shorteners
Use branded, recognizable domains to improve trust and reduce filtering risk
Consent and Opt-In
All recipients must provide clear and verifiable consent before receiving messages
Messaging must align with registered use cases (e.g., A2P 10DLC campaigns)
Carrier Enforcement
Carriers may take action based on:
Message content and classification
End-user complaints or opt-out rates
Sending patterns and traffic anomalies
Enforcement can occur even if content is not explicitly listed above.
Best Practices
To maintain compliance and optimize deliverability:
Register your messaging campaigns where required (e.g., 10DLC)
Clearly identify your brand in each message
Provide transparent opt-in and opt-out mechanisms
Use compliant language and avoid misleading claims
Send only relevant, expected communications to opted-in users