How to Troubleshoot SMS Delivery Failures in Sparkforge

By Sparkforge Support Team ·Last reviewed May 3, 2026

Most Sparkforge SMS failures trace to DND status, landline numbers, ramp-up limits, or carrier-level blocks. Check the conversation view for the error code, then apply the matching fix below.

When a text message does not reach a contact, the failure happens at one of three layers: the Sparkforge account layer, the carrier API layer, or the recipient carrier network. Each layer surfaces a specific error you can act on.

Where to find the error

Open Conversations and look for a red error badge on the failed message. The message and code shown there point to the exact cause.

Account-layer issues

Contact has DND enabled — Remove the Do Not Disturb flag on the contact or channel to resume sending.
Number is a landline — Use a mobile number, or disable number validation if the contact is reachable another way.
New sub-account ramp-up — Sparkforge limits new accounts to prevent spam. Wait for limits to lift, or request a manual increase.
Daily message cap reached — Bulk and automated messages stop once the daily limit is hit. Adjust limits in agency settings or wait until the next day.
Suspended for high errors or complaints — Follow deliverability best practices and contact support to lift the suspension.

Carrier API errors

Carrier DND list — The contact must text START back to the same Sparkforge number to opt in again.
30001 Queue overflow — Messages stuck in queue over four hours fail. Reduce the validity period in messaging settings.
30002 Suspended sub-account — Contact support to clear the suspension.

Recipient carrier errors

30003 Unreachable handset — Phone is off, out of signal, or a landline. Retry later or verify the number is mobile.
30004 Message blocked — Number is blocked, opted out, or on a do-not-call registry. Confirm consent and validity.
Attachment too large — File exceeds carrier MMS limits. Compress or split the attachment.
International permissions — Account may not be cleared for international SMS. Contact support to enable.
Body too long — Trim the message or remove {{message.body}} custom values that pull in oversized email replies.

Pre-send checklist

Check Conversations for an error badge.
Match the error code to the table above.
Apply the listed fix.
Resend and confirm delivery.

Charges apply once a message is attempted, even if it fails downstream. Validate numbers and consent before sending bulk campaigns.

Frequently Asked Questions

Why am I being charged for failed SMS messages?

Carriers bill for the send attempt, not delivery. Once Sparkforge hands the message to the carrier, the charge is recorded even if it fails at the recipient's network.

How do I find the exact reason a message failed?

Open the conversation in Sparkforge and read the error code on the failed message. For deeper diagnostics, review the underlying carrier logs.

What does error 30003 mean?

30003 is an unreachable handset. The phone may be off, out of signal, a landline, or experiencing a carrier issue. Retry later or verify the number is a working mobile line.

How do I get a contact off the carrier DND list?

The contact must text the word START back to the same Sparkforge number. Only the recipient can re-enable messaging — you cannot remove them from the carrier DND list on your end.

Why are my new account's messages limited?

Sparkforge ramps new sub-accounts gradually to protect sender reputation and meet carrier compliance rules. Limits increase automatically, or your agency can request a lift.