How do I check SMS carrier errors?

To check SMS carrier errors, the exact method depends on what you’re using to send SMS:

1) If you use an SMS API provider

Most providers expose delivery and error details in their dashboard or API logs.

Common places to check

• Message logs / message history
• Delivery receipts (DLRs)
• Error codes / callback webhooks
• Carrier response fields

What to look for

• Undelivered or failed status
• Error code returned by the provider
• Carrier rejection reason if available
• Spam/filtering indicators
• Opt-out / blocked recipient status

Examples of common causes:

• Invalid phone number
• Unreachable carrier/network
• Message content filtered as spam
• Recipient has opted out
• Unsupported sender type
• Carrier rate limiting

2) If you’re troubleshooting a single message

Check whether your provider gives:

• Submission status: accepted by API
• Delivery status: delivered to handset/carrier
• Failure status: rejected by carrier or handset

If a message was accepted by the API but not delivered, the issue is usually at the carrier or handset level.

3) If you want carrier-specific diagnostics

You may need:

• DLR webhooks from your provider
• Error code mapping from their docs
• Support ticket with the message ID, timestamp, destination number, and error code

4) If you’re using a phone manually

Look for:

• Message not sent
• Red exclamation / failed to send
• No delivery report
• No service / blocked SMS
• Carrier-specific filtering

5) Best data to collect

When checking an SMS carrier error, gather:

• Destination number
• Sender ID / phone number
• Timestamp
• Message ID
• Provider error code
• Delivery status
• Country/carrier
• Message content

If you tell me which SMS provider you’re using (Twilio, Sinch, MessageBird, AWS SNS, etc.), I can show you exactly where to check carrier errors and how to interpret the codes.