Compliance guidelines

To use SMS messaging responsibly, businesses must follow all applicable legal, regulatory, and industry standards. Compliance helps ensure that messages are delivered successfully, recipients' privacy is protected, and the organization avoids penalties or account restrictions.

Compliance considerations that directly affect SMS deliverability include sender identification, opt-in requirements, content restrictions, and traffic filtering. For country-specific requirements, always refer to SMS coverage and connectivity.

For a complete overview of Infobip compliance principles that apply across all channels, including data protection, acceptable use, and platform-wide policies, see the Essentials compliance section.

Regulations and compliance [#regulations-and-compliance]

Every country has different rules and terms of usage according to their national law. Depending on your region or target country, you must comply with SMS regulations:

• Recipient consent: Obtain explicit user opt-in before sending SMS
• Opt-out: Support STOP or similar keywords
• Carrier regulations: U.S. carriers require registration of campaigns for A2P (Application-to-Person) traffic
• Data privacy: Follow local regulations such as GDPR, TCPA, and CAN-SPAM, depending on region

Recipient consent [#recipient-consent]

Capturing and managing recipient consent is essential for compliant and effective SMS communication. Infobip SMS supports this through opt-in, opt-out, and blocklists (Do Not Contact lists).

These features ensure that messages are sent only to recipients who have given permission to receive them. They also help your organization align with data protection regulations such as GDPR and CCPA.

Opt-in [#opt-in-recipient-consent]

Permission-based marketing is critical to making campaigns successful and ensures that you are compliant with regulatory laws. The opt-in feature enables users to send a text message to join an SMS list, which gives a business permission to send marketing messages and other alerts.

Opt-out [#opt-out-recipient-consent]

The opt-out feature enables end users to select a URL added to the end of the received SMS to unsubscribe from further SMS messages from that alphanumeric sender.

Opt-out is required because:

• Some alphanumeric senders must always have a URL opt-out option
• Required for all channels and all regions
• Required information for setting up a blocklist

Blocklists [#blocklists-recipient-consent]

Blocklists store phone numbers and email addresses that no longer wish to receive communication. When a recipient opts out, Infobip adds the destination to the Do Not Contact list and prevents further messages from being sent.

If you manage multiple accounts, you can assign blocklist records to a specific account. When the platform detects a message addressed to a blocklisted destination, the message is rejected.

Infobip automatically creates blocklist records in the following scenarios:

• A recipient replies with a specific SMS keyword, such as STOP
• A recipient clicks an opt-out link included in an SMS message
• A communication flow in Moments triggers a blocklist action

You can also create blocklists manually:

• Blocklist API using Create blocklists
• People data platform using the Do Not Contact list

Campaign registration (USA and Canada) [#campaign-registration]

Campaign registration for SMS messaging is the process of registering your SMS campaign details with mobile operators or regulatory authorities before sending messages. This is particularly important in the United States and Canada, where A2P (Application-to-Person) messaging is tightly regulated.

If you are sending A2P traffic over 10DLC in USA and Canada:

• Register your brand and campaign with The Campaign Registry (TCR) using the US Sender Registration app
• Provide message samples, use cases, and opt-in workflows

See US Sender Registration for step-by-step instructions on registering your brand and campaign.

Toll-free SMS numbers [#toll-free-sms-numbers]

Toll-free SMS numbers have a mandatory opt-out layer that is enforced at the carrier or aggregator level. This behavior is external to Infobip and cannot be disabled or customized.

Opt-out (STOP) handling [#toll-free-opt-out-toll-free-sms-numbers]

When an end user sends STOP to a toll-free SMS number:

• The toll-free number is blocked from sending further SMS messages to that end user at the network layer
• The block applies regardless of any Infobip keyword configuration or application logic
• The carrier or aggregator sends an automatic response confirming the unsubscribe

Opt-in (START or UNSTOP) handling [#toll-free-opt-in-toll-free-sms-numbers]

When the same end user later sends START or UNSTOP to the toll-free SMS number:

• The previously applied block is removed at the network layer
• The toll-free number can send SMS messages to that end user again