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Android SMS Gateway Troubleshooting: Carrier rejected

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Android SMS Gateway Troubleshooting: Carrier rejected. KB article diagnosing carrier rejected. Symptoms, likely causes, validation steps, recovery. Priced by devices and SMS send volume; BYO phone and operator credit.

Written by the SMS Gateway team for operators who run phones and airtime themselves — not for theoretical cloud SMS demos.

InformationAndroid SMS GatewayTroubleshootingOperations
Article
Published
August 13, 2025
Updated
August 26, 2025
Reading time
16 minute read

Key Takeaways

  • android sms gateway troubleshooting carrier rejected: the operator refused the PDU. A 2xx from POST /messages already happened.
  • Separate HTTP errors, pairing, empty airtime, and true carrier reject before you change application code.
  • Spammy copy, purchased lists, and unregistered bulk get numbers barred. That is not a gateway bug.
  • Retries still burn operator SMS. Idempotency and a pause beat a loop.
  • Priced by devices and SMS send volume. You use your own phone and operator SMS credit. We do not refund carrier rejects as platform credits.
  • Free 300 SMS lifetime is for canaries, not for hammering a barred MSISDN.

On-call searches android sms gateway troubleshooting “carrier rejected” after a DLR that is not Pending. Start by splitting layers. Docs: Developer Center. DLR lookup is GET /messages/{id}; production prefers webhooks.

Priced by devices and SMS send volume. You use your own phone and operator SMS credit.

If the same template was rejected on three operators, the SIM is not unlucky. The copy or the list is the incident.

Rejected is usually radio, not JSON

401/422 are your client. Pairing down is the phone. Reject after send is the operator or the destination network. Do not “fix” it by inventing a new host.

Reject vs fail vs pending

What you seeLikely layerFirst move
HTTP 4xx/5xx on POSTAPI / auth / bodyKey, E.164 to[], docs
Queued, never leaves phoneDevice / OEM / airtimeCharge, pairing, SMS balance
Sent then failed/rejectedOperator / destinationCopy, consent, SIM reputation
Pending foreverNo DLR (common) or stallDo not treat all Pending as reject

Wording and lists

Promo language, URL shorteners, purchased CSVs. Spammy wording. India/Nigeria bulk is not a handset loophole. STOP.

Empty wallet is not a reject stamp

Zero SMS balance often looks like stall, not a branded “rejected.” Check the operator wallet before rewriting templates.

Do not retry-storm

Idempotency on user-visible OTP. JSON API. Pace. Carrier fair-use still applies — this is not unlimited send.

OTP playbook is different

Keep codes boring, GSM-7 if you can, isolated device. OTP. A reject on promo must not move that blast onto the auth SIM.

Checklist

  • HTTP vs DLR vs pairing split on paper.
  • Same template on a staff SIM / second operator.
  • List consent; no dump files.
  • Pause retries on content rejects.
  • Airtime and OEM checked.
  • Webhook message.failed logged without OTP bodies.

Next steps

Fix the layer you proved, not the one that is easiest to restart. Setup · devices + volume.

Related product pages

Jump to the live product docs for this topic—not another long-form article.

FAQ

Frequently asked questions

Direct answers about android sms gateway troubleshooting carrier rejected.

The API returned success but the carrier rejected the SMS. Is the API down?

Usually no. The control plane accepted the job. Delivery is a radio/operator outcome. Check DLR and webhooks message.failed.

Should I retry every reject immediately?

No. Content and reputation rejects get worse when you hammer. Fix copy, list, or registration. Pace technical retries.

Does a reject refund operator credit?

Operator billing varies; we do not sell airtime. Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
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