Penalties for Non-Compliant Messaging

Last updated on February 27, 2025

SMS to Slack is committed to running a fully compliant service, in both the letter and spirit of the law.

U.S. carriers have implemented A2P messaging channels, toll-free numbers, and 10-digit long codes (A2P 10DLC) to provide senders with an authorized channel for messaging that ensures consumers consistently receive wanted messages. Messaging campaigns that do not comply with carrier requirements may incur penalties for the non-compliant traffic.

Carrier policies are integrated into SMS to Slack's policies. Any inability by SMS to Slack to halt non-compliant traffic does not constitute grounds for dispute. If these penalties are imposed, they will be passed directly on to the customer by SMS to Slack. Below is a breakdown of the current non-compliance fines, best practices for maintaining compliance, and our FAQ regarding these fines.

Article Contents

AT&T and T-Mobile Carrier Fines for Unregistered Long Code Messaging

Effective September 1st, 2023, all SMS and MMS messages sent to U.S. phone numbers using +1 10DLC phone numbers must be routed through an approved application-to-person (A2P) campaign. Messages sent to the U.S. using unregistered 10DLC numbers will be blocked. Blocked messages will return an error stating, "Message could not be delivered because this phone number is not associated with an active 10DLC Campaign." SMS to Slack messaging rates will continue to apply even for blocked messages, though no per-message carrier fines will be imposed.

T-Mobile Penalties for Non-Compliant Messaging

The following fines are specific to T-Mobile. If these fines are assessed by T-Mobile (or other U.S. carriers), they will be passed directly to customers by SMS to Slack.

Content Violation

Content that violates carrier policies—as outlined in SMS to Slack's Acceptable Use Policy—including spam, phishing, and SHAFT violations (Sex, Hate, Alcohol, Firearms, Tobacco).

Fine: $10,000 per violation

Enforcement: This fine is applied at T-Mobile's discretion, with a warning issued prior to enforcement. SMS to Slack will forward this warning via email to users on your SMS to Slack account who are subscribed to Compliance and Regulatory alerts. This initial warning offers an opportunity to achieve compliance without incurring a fine.

Should another violation occur after the warning, SMS to Slack will notify you and pass the fine directly on behalf of T-Mobile. You agree to pay any and all third party fines you incur them through the use of SMS to Slack.

Messaging Program Evasion

Utilizing filtering evasion techniques—such as snowshoeing and recycling numbers (releasing/purchasing new numbers), to dilute a number’s reputation.

Fine: $1,000

Enforcement: SMS to Slack will report these violations to customers and pass the fines directly on behalf of the carriers.

Sev-0 Fines on Prohibited A2P Traffic

T-Mobile has implemented A2P 10DLC non-compliance fines for messages containing prohibited content. If T-Mobile identifies any messages that breach the tiers listed below, they will issue a Sev-0 violation (the most severe consumer violation), impose a non-compliance fine, and SMS to Slack will immediately block the offending messages.

This applies to all commercial messaging non-consumer A2P products (SMS or MMS, toll-free, and 10DLC) that pass through the T-Mobile network.

Because Sev-0 violations also infringe on SMS to Slack's Acceptable Use Policy, SMS to Slack will pass these fines on to you for every Sev-0 violation, starting February 15, 2024. These fines include, but are not limited to, the following:

  • Tier 1: $2,000: phishing (including simulated phishing for security testing or similar purposes), smishing, and social engineering
    • Social engineering is a tactic used to manipulate someone into disclosing sensitive information, such as passwords or credit card numbers.
  • Tier 2: $1,000: illegal content (content must be legal both federally and in all 50 states)
  • Tier 3: $500: all other violations in commercial messaging, including but not limited to SHAFT (sex, hate, alcohol, firearms, and tobacco) that do not comply with federal and state laws and regulations (e.g., age-gate).

These non-compliance fines apply to violations across any A2P messaging product (SMS/MMS, toll-free, and 10DLC).

T-Mobile reserves the right to permanently suspend any brands, campaigns, or your company's access to the T-Mobile Network if violations are deemed excessive. Should you incur these fines, SMS to Slack will send a Sev-0 violation notice and subsequently charge the corresponding fine amount.

For further details, please review T-Mobile's Code of Conduct Section 5: Prohibited Campaign Content.

How to Avoid Carrier Fines for Non-Compliant Messaging

Ensure Compliance with SMS to Slack's Policies

The most effective method to avoid fines for non-compliance is to ensure your traffic adheres to SMS to Slack's Acceptable Use Policy and T-Mobile's Code of Conduct. You may also consult CTIA's Best Practices documentation and integrate industry standards into your operations and/or services.

Monitor Your Traffic

Message filtering and opt-out rates can serve as early indicators of non-compliant messaging. Regularly monitoring your traffic is a best practice for ensuring compliance.

Non-Compliant Messaging Fines FAQ

How will penalties be issued to customers?

Penalties imposed via SMS to Slack will be passed directly to customers and will appear on their invoices.

What does “snowshoeing” mean in the context of messaging?

Snowshoeing refers to the practice of distributing similar or identical messages across multiple phone numbers with the intent or effect of evading detection and prevention mechanisms for unwanted messaging.

I use multiple numbers in my Messaging Service for my use case. Would that be considered snowshoeing?

This is not considered snowshoeing unless you are deliberately sending the same or similar message across more numbers than necessary to evade detection or filtering, or to dilute a number’s reputation—that is, to prevent it from being marked as ‘spam’ by the carriers.

For example, not snowshoeing would be utilizing area code geomatch with multiple numbers to create localized experiences.

Will the Content Violation notification come specifically from SMS to Slack?

Customers will receive notifications and passthrough fines for non-compliance directly from SMS to Slack.

Is a Sev-0 fine counted per message segment or per violation?

Each Sev-0 fine applies to the individual violation. For instance, if a customer receives a Sev-0 violation for a phishing attack sent across 1,000 message segments, they would be charged one Sev-0 fine for the entire violation.

Will SMS to Slack suspend my traffic and assist with remediation BEFORE the fine?

T-Mobile will issue a warning prior to imposing the discretionary Content Violation fine described above, and SMS to Slack will relay this warning via email to users on your SMS to Slack account.

However, for automatic violations such as the Sev-0 fines, no warning is provided, and those fines are passed through simultaneously with other enforcement measures.

Please note that SMS to Slack also proactively enforces its own policies independently of carriers through outreach and other remediation efforts—including account restrictions or suspension. Nonetheless, SMS to Slack does not guarantee intervention in your non-compliant traffic before carriers impose fines.

Is there an appeals process if I believe I have been incorrectly fined for a compliance violation?

SMS to Slack will conduct an independent investigation into any reported compliance violations raised by carriers and will work with you to appeal if the penalty appears to have been applied in error.