Understanding short codes
Short codes are 5-6 digit numbers optimized for high-volume, high-speed A2P (Application-to-Person) SMS messaging. Unlike standard phone numbers, short codes are dedicated to a single organization, country and carrier-specific, and designed for brand recognition at scale.
Short code characteristics
- Format: 5-6 digits (for example, 12345, no country code prefix)
- Channels: SMS, MMS (no voice)
- Ownership: Always dedicated (never shared)
- Cost: High
- Setup time: 2 to 4 weeks
- Throughput: Very high - optimized for rapid messaging (>50-100 messages per second)
- Approval: Requires individual carrier approval (AT&T, T-Mobile, Verizon, and similar carriers) and certification testing for some carriers
When to use short code
Consider using short code for:
- High-volume SMS campaigns
- Time-sensitive marketing (flash sales, urgent alerts)
- Rapid messaging at scale (more than 50 to 100 messages per second)
- Brand recognition through a memorable 5 to 6 digit number
- Contest voting or premium content signup programs
- Two-factor authentication (OTP)
Not ideal for:
- Transactional-only messaging (use 10DLC instead)
- Low-volume programs (expensive)
- Programs that need to launch quickly (2-4 week timeline)
Short code registration process
Short code registration involves multiple steps and carrier approvals.
Get a short code
Purchase through the web interface. See Get started with short codes Stage 1 for detailed steps.
Create or associate a brand
See Understanding brands for complete details.
Create campaign
See Get started with short codes Stage 2 for detailed steps.
Infobip compliance review
Checked for basic compliance against CTIA rules and carrier policies.
Carrier submissions
Campaign sent to individual carriers (AT&T, T-Mobile, Verizon, etc.) for independent review.
Certification (if required)
T-Mobile and Verizon MMS may require certification testing after carrier approval.
Campaign goes live
Begin sending messages. Total timeline: 2 to 4 weeks from submission to live on all networks.
Brand and campaign registration for short code
Brand registration [#brand-registration-brand-and-campaign-registration-for-short-code]
For complete brand guidance, see Understanding brands.
For short codes:
- Brand registration is via web interface only (API not available)
- Associate your brand with the short code during purchase (mandatory; cannot be done separately)
- Select CREATE NEW BRAND during purchase to register a new brand; it submits automatically for verification
- Any changes to short code lease management require brand re-vetting
Campaign registration [#campaign-registration-brand-and-campaign-registration-for-short-code]
For complete campaign guidance, see:
- Understanding campaigns: What campaigns are, requirements, fields, and general process
- Get started with short codes: Step-by-step instructions (Stage 2: Create and register campaigns)
| Aspect | Details |
|---|---|
| Registration method | Web interface only (API not available) |
| Approval process | Infobip compliance review > Individual carrier submissions (AT&T, T-Mobile, Verizon, US Cellular) > Per-carrier approvals |
| Timeline | 2 to 4 weeks typical (1 to 5 days Infobip review; 3 to 10 days for Tier 1 operators; Tier 3 operators can take up to 4 weeks) |
| Carrier-specific requirements | T-Mobile and Verizon MMS require certification testing after approval. Monitor per-carrier approval status in the US Sender Registration web interface. |
| Two-way messaging | Supported. Configure keywords (STOP, HELP) and routing before submitting for campaign approval, as routing is required for certification testing. |
| Campaign statuses | Draft > Submitted for review > Action required > Approved by internal reviewer > Approved for submission > Submitted > Registered |
Short code campaign statuses
Short code campaigns move through these specific statuses:
| Status | Description | Action |
|---|---|---|
| Draft | Campaign is still being drafted and has not been submitted to Infobip. Campaigns in this status are not monitored by Infobip. | Complete all required fields and submit for review |
| Submitted for review | Campaign brief is ready and has been submitted to the Infobip Compliance team for review. Infobip provides feedback on the submission. | Wait for Infobip review (1 to 3 days typical) |
| Action required | The Infobip Compliance team has found issues with your campaign that you must resolve. Issues are listed under the Issues tab in campaign details. | Review issues, fix them, and resubmit campaign for re-review |
| Approved by internal reviewer | Campaign has been approved by the Infobip Compliance team and is fully compliant. | Await automatic submission to carriers |
| Approved for submission | Campaign has passed Infobip Compliance review and is confirmed fully compliant with CTIA guidelines and operator-specific requirements. Ready for carrier submission. | Infobip submits automatically to carriers |
| Submitted | Campaign has been submitted for review and approval by individual carriers (AT&T, T-Mobile, Verizon, US Cellular, and similar carriers). Certification testing occurs during this phase for T-Mobile and Verizon MMS campaigns. | Wait for individual carrier approvals; monitor Network Status tab for per-carrier progress |
| Registered | Campaign has been approved by all carriers and is ready for launch. You can begin sending messages immediately. | Begin sending SMS traffic through the short code |
| Rejected | Campaign is not compliant with CTIA guidelines and operator-specific requirements and has been rejected by the Infobip Compliance team. Used only in extreme cases when campaign purpose is not aligned with guidelines. | Review rejection reasons, create new campaign addressing feedback, or appeal if eligible |
Handling issues [#handling-issues-short-code-campaign-statuses]
If your campaign shows Action required status:
- Log in to US Sender Registration web interface
- Open your campaign
- Select the Issues tab under campaign details
- Review each issue listed with the specific problem
- Fix the issue in your campaign (message samples, use case, keywords, etc.)
- Resubmit campaign for re-review
- Await Infobip decision (1 to 3 days)
- If new issues found, repeat the process
- Once compliant, campaign moves to Approved for submission status
Certification process (T-Mobile and Verizon MMS)
What is certification? [#what-is-certification-certification-process-t-mobile-and-verizon-mms]
Certification is the process by which your campaign is validated and approved by both Infobip and the mobile operators (MNOs). Certification ensures your setup and messaging mechanism work exactly as submitted and that auto-responders are fully functional.
When certification is required [#when-certification-is-required-certification-process-t-mobile-and-verizon-mms]
- T-Mobile short codes: Required for all short codes
- Verizon MMS short codes: Required
What happens during certification [#what-happens-during-certification-certification-process-t-mobile-and-verizon-mms]
Infobip and the carrier test that your campaign behaves exactly as submitted. Your setup and sending mechanism must be fully ready for this testing.
Infobip and operators will test:
- Confirmation MT (Mobile Terminated message): Initial confirmation message
- HELP keyword response: Ensure HELP auto-responder triggers correctly
- STOP keyword response: Ensure STOP opt-out functionality works
- Message formatting and content: Verify messages match submission
- MMS content display (if applicable) - Validate MMS rendering
- All auto-responders functional: Ensure all keyword responses work
CRITICAL: Any mismatches in the content of your messages from the original submission may result in delays during testing. Your auto-responders must be ready to respond correctly.
Certification timeline [#certification-timeline-certification-process-t-mobile-and-verizon-mms]
- Duration: 2 to 5 business days typical
- Process: Infobip sends three test messages to your short code: one for opt-in, one for HELP, and one for STOP
- Validation: If all three responses match your submission exactly, Infobip submits your short code to the operators for their own testing phase.
- Retest: If issues found, Infobip contacts you to fix the behavior, then retests
Common certification issues [#common-certification-issues-certification-process-t-mobile-and-verizon-mms]
| Issue | Cause | Solution |
|---|---|---|
| STOP response mismatch | Actual response differs from submission, or no response to STOP keyword at all | Update system to match submitted response exactly |
| HELP message incorrect | Help message content does not match submission, or no response to HELP keyword at all | Fix auto-responder to match submission exactly |
| No test available for opt-in | Opt-in mechanism is not available for testing, or no keyword was provided | Update system to ensure confirmation MT is sent, or provide a test keyword |
| MMS not displaying | Content or format issue | Verify MMS content and format |
| Message flow wrong | Keywords routing incorrectly | Fix routing logic in system |
If issues are found during certification, Infobip will contact you to fix the behavior and then retests your system.
Carrier provisioning timelines
Once campaign is approved by Infobip Compliance, it is submitted to individual carriers for approval and provisioning.
Carrier-specific timelines [#carrier-specific-timelines-carrier-provisioning-timelines]
| Carrier | Typical Timeline | Provisioning Day | Notes |
|---|---|---|---|
| AT&T | 2 business days | Daily | AT&T provisions daily; new short codes are provisioned 2 business days after submission |
| T-Mobile | 1 to 2 weeks | N/A | Takes 3 to 5 business days to approve and provision new short codes. All short codes require certification testing after provisioning. |
| Verizon | 1 to 2 weeks | Typically Monday | Provisions every Monday. Two provisioning cycles may be required. Short codes with MMS require certification testing after provisioning. |
| US Cellular | 3 to 5 business days | N/A | SMS provisioning completed within 3 to 5 business days. MMS is provisioned on Thursdays, so expect up to 7 days for MMS if submitted on a Thursday. |
| Interop | 24 hours | N/A | Typically completes new short code provisioning within 24 hours. Provisions twice per month. |
| Clearsky | 24 hours | N/A | Provisions daily. Typically provisioned within 24 hours of the request. |
| Google Voice | 2 weeks+ | N/A | Does not have a typical provisioning schedule. Provisioning is completed upon request and takes at least two weeks on average. |
Network status tracking [#network-status-tracking-carrier-provisioning-timelines]
Once your campaign has been approved by the Infobip Compliance team and submission to carriers has started, you can track the approval status for each carrier:
- Go to Campaigns tab in US Sender Registration web interface (Channels and Numbers > Tools & Compliance > US Sender Registration)
- Select your campaign
- Select the Network Status tab
- See per-carrier status
Network status definitions:
| Status | Description |
|---|---|
| Not registered | Campaign has not been submitted to carrier |
| Pending | Campaign has been submitted to carrier and is pending carrier feedback |
| Certification | Campaign is being certified by the Infobip team and the carrier (T-Mobile and Verizon only; other carriers do not require certification) |
| Approved | Campaign has been approved by carrier |
Campaign amendments
If you have a campaign that is already live and you need to change it, you can request an amendment. This allows you to modify your campaign without creating a completely new one.
When to amend vs. create a new campaign [#when-to-amend-vs-create-a-new-campaign-campaign-amendments]
- Use amendment: For minor changes to campaign parameters (message frequency, call-to-action, support info, and similar details)
- Create new campaign: For major changes to messaging content, use case, or MMS support
Parameters you can amend [#parameters-you-can-amend-campaign-amendments]
You can amend the following parameters on an existing campaign:
- Campaign summary: Update campaign description
- Use cases: Change use case classification
- MMS support: Add or remove MMS capability
- Frequency: Update message frequency (for example, from "1 to 2 per week" to "daily")
- Call-to-action: Modify how users opt-in
- Support information: Update contact details for customer support
- Additional information: Change other campaign details
How to amend a campaign [#how-to-amend-a-campaign-campaign-amendments]
- Go to Campaigns tab in US Sender Registration web interface
- Find your live campaign (status must be Registered)
- Select Amend campaign
- Make the necessary changes to the parameters
- Submit the amendment
- Infobip reviews the amendment (1 to 3 days typical)
- Once approved, changes take effect immediately
Get started with short codes
Complete step-by-step walkthrough from purchase through campaign launch.
Migrating USA short codes
Import existing USA short codes from another provider.
USA SMS compliance requirements
CTIA standards, consent model, and carrier compliance rules.