International SMS delivery depends on the rules established by the destination country's regulators and mobile carriers. The United Kingdom requires compliant sender types and regulatory approval for UK long codes, while Turkey blocks international A2P SMS containing URLs as of April 1, 2026.

This guide explains the requirements that affect platform-managed and externally connected phone numbers, the actions needed to remain compliant, and the error codes you may see when a message is blocked.

What is International SMS Compliance?

International SMS compliance refers to the country-specific rules that determine which sender types, registrations, and message content can be used when sending Application-to-Person (A2P) messages. A sender that works for one destination may not be eligible for another because carriers and regulators apply different requirements by country.

For the United Kingdom, sender identity and UK long-code registration are central requirements. For Turkey, the primary international restriction covered here is the prohibition on URLs and links in international A2P SMS.

Key Benefits of International SMS Compliance

Following destination-specific requirements helps reduce preventable message failures and makes it easier to identify whether a delivery problem is caused by sender eligibility, registration, message content, or carrier filtering.

• Improved Deliverability: Use sender types and message formats accepted by the destination country's carriers.
• Reduced Message Failures: Avoid unsupported routes, unregistered sender types, and prohibited content.
• Clearer Troubleshooting: Recognize errors such as 21612 and 30007 and understand what they indicate.
• Regulatory Readiness: Keep UK long-code KYC and Regulatory Compliance requirements up to date.
• Safer Automation: Update workflows, campaigns, and templates before country-specific restrictions cause delivery failures.

United Kingdom SMS Compliance

UK carriers restrict A2P messaging from unsupported international long codes and require UK long codes to be connected to approved Regulatory Compliance information. Choosing the correct sender type and completing the required verification are essential before relying on a UK number for business messaging.

UK Enforcement Timeline

The UK requirements were introduced in stages. The dates below help distinguish the original international long-code restrictions from the later Regulatory Compliance requirements for UK long codes.

Supported UK Sender Options

The appropriate sender depends on whether you need local two-way messaging, branded one-way messaging, or a higher-volume messaging solution.

• UK Long Code: Requires applicable KYC information and an approved Regulatory Compliance bundle.
• Alphanumeric Sender ID: Suitable for supported one-way branded messaging use cases.
• Short Code: An option for supported higher-volume messaging use cases that require dedicated provisioning.

UK KYC and Regulatory Compliance Requirements

UK long-code users must provide identity or business information appropriate to the number type. The exact information can vary based on whether the number is local, national, mobile, or toll-free and whether the registrant is an individual or business.

Common information can include the registrant's name, business name, registered address, business registration details, authorized representative information, contact information, and supporting verification documents when required.

How to Meet UK Registration Requirements

The registration path depends on whether the number is managed directly within the platform or through an externally connected phone provider. Use the registration interface associated with your phone-number configuration.

For Platform-Managed Numbers

Platform-managed UK numbers use the Regulatory Bundle and Address tools available under Phone System. Complete the required KYC information and ensure the appropriate approved bundle is associated with the UK number.

1. Go to Settings → Phone System.
2. Open Regulatory Bundle / Address.
3. Create or open the applicable UK regulatory bundle.
4. Enter the required KYC information and upload supporting documents when requested.
5. Submit the bundle for review.
6. Associate the approved bundle with the applicable UK long code.

Regulatory Bundle / Address is used to create and manage required UK regulatory information for platform-managed phone numbers.

Purchasing a UK Number

When purchasing a UK number, review the number's capabilities and address requirements before completing the purchase. Numbers that require regulatory information must be connected to an approved bundle as part of the compliant setup.

Review UK number type, capabilities, and regulatory requirements before completing the purchase.

For Externally Connected Phone Providers

If your phone numbers are managed through an externally connected provider account, UK number purchasing and Regulatory Compliance bundle management are completed directly through that provider rather than through the platform-managed registration interface.

1. Open your connected provider's management console.
2. Create and submit the applicable UK Regulatory Compliance bundle.
3. Provide the required KYC information and documentation.
4. Purchase or configure an eligible UK sender.
5. Monitor failed messaging traffic and update non-compliant routes as needed.

Turkey SMS Compliance

Effective April 1, 2026, Turkey's Information and Communication Technologies Authority (BTK) requires mobile operators to block international A2P SMS containing URLs. This restriction affects message content rather than only promotional traffic, so transactional and authentication messages must also be reviewed.

Content That Must Be Removed

Review every SMS template, workflow, campaign, and automated notification that can send to a Turkish recipient. Links inserted dynamically by a custom value should be treated the same as links written directly into the template.

• Full website URLs
• Public or branded shortened URLs
• Tracking links
• Hyperlinks or internet addresses
• Dynamic fields that resolve to a URL

Messages Covered by the Rule

The restriction is not limited to marketing messages. International A2P messages containing URLs can be blocked regardless of the business purpose of the message.

• Order confirmations
• Shipping updates
• Appointment reminders
• Transactional notifications
• One-time passcodes (OTPs)

Error 30007 and Turkey

Messages blocked by a Turkish carrier because of the URL restriction may return Error 30007. However, Error 30007 is a general carrier-filtering error and does not uniquely identify the Turkey URL rule.

The same error can occur when a carrier filters a message because of its content, sender identity, consent, or another compliance requirement. Always review the destination country, message body, sender, and applicable compliance rules before determining the cause.

If You Have a Local Turkish Business Entity

Businesses formally registered in Turkey that must continue sending URL-containing SMS can use the documented local pathway for this requirement. This requires local business eligibility and additional provider configuration.

1. Establish a direct contract with Posta Güvercini.
2. Authorize Posta Güvercini as the service provider through the Turkish Message Management System (IYS).
3. Contact Support to complete the applicable technical setup and routing.

Good to Know: If you do not have a qualifying local Turkish business entity, remove URLs from international SMS sent to Turkish recipients.

How to Prepare for UK and Turkey SMS Compliance

A proactive compliance review helps identify unsupported senders and prohibited message content before customers experience delivery failures. Check both your phone-number configuration and every automation capable of sending internationally.

1. Identify the destination countries you message.
   Confirm whether your workflows, campaigns, or users send SMS to UK or Turkish recipients.
2. Review the sender used for UK traffic.
   Do not rely on an unsupported international long-code route. Use an eligible UK sender and complete the applicable registration.
3. Complete UK KYC and Regulatory Compliance requirements.
   For platform-managed numbers, manage the bundle through Phone System. For externally connected provider accounts, complete the applicable registration through the provider.
4. Review US-to-UK messaging routes.
   If messages originate from a US number and are sent to the UK, update the route because this combination is not supported and can return Error 21612.
5. Audit SMS content sent to Turkey.
   Search workflows, campaigns, templates, custom values, and automated notifications for URLs, shortened links, or tracking links.
6. Replace links in Turkish SMS.
   Use URL-free instructions, a phone number, or another communication channel when the recipient needs additional information.
7. Test and monitor delivery.
   Send controlled test messages and review message errors so unsupported sender routes or carrier filtering can be identified quickly.

Troubleshooting International SMS Delivery

International message failures should be investigated by checking the sender country, destination country, sender type, registration status, message content, and delivery error together. An error code alone may not identify every compliance issue.

Frequently Asked Questions

Need Help?

If international SMS messages are still failing after reviewing the applicable country requirements, check the sender, registration status, destination, message content, and delivery error before contacting Support.