Sparkforge Phone System Error Codes and Warnings

The Sparkforge Phone System returns numbered error codes when a message or call fails. Each code points to a specific issue — a malformed number, an opt-out, carrier filtering, an A2P registration gap. Use this reference to diagnose and resolve issues before they pile up in support tickets.

21211: Invalid "To" Phone Number

The destination number is invalid or formatted incorrectly. Sparkforge requires E.164 format: [+][country code][subscriber number].

Common Causes

• Number not in E.164 format
• Sending from a Sparkforge number to itself
• Sending to a Short Code or Alphanumeric Sender ID (these can't receive)
• Sending via a Messaging Service to a number with an invalid prefix

Fixes

• Reformat numbers to E.164.
• Confirm the country calling code is correct.
• Don't send from a Sparkforge number to itself.
• Drop invalid prefixes when sending via a Messaging Service.

21408: Account Not Allowed to Send to This Region

You tried to send SMS or MMS to a region not enabled on your account. This protects against unintended international charges.

Causes

• Region not enabled in account settings.
• Region not supported — e.g., recipients in Iran (effective March 15, 2025, voice, messaging, and email traffic to Iran is blocked, including +98 prefixes for WhatsApp and RCS).

Fix

Contact Support to enable a supported region.

21614: "To" Number Is Not a Valid Mobile Number

The destination is a landline, an invalid number, or an IoT/M2M number Sparkforge hasn't validated.

Fixes

• Use the Lookup API to confirm the number is mobile.
• Verify E.164 formatting.
• For IoT/M2M numbers, contact Support if the number format is non-standard.

21635: "To" Number Is a Landline

The destination is a landline and can't receive SMS. If you're sure the number is mobile, contact Support.

21661: "From" Number Is Not SMS-Capable

The sending number doesn't support SMS.

Fixes

• Check capabilities in Settings → Phone Numbers → Manage Number.
• Purchase an SMS-capable number from + Add Number.

30002: Account Suspended

The message failed because the account was suspended after the message queued but before it sent.

Causes

• Suspension for lack of funds.
• Suspension for an Acceptable Use Policy violation.

Fix

Contact Support.

30003: Number Unreachable or Out of Service

The destination handset is off, out of signal, or otherwise unavailable.

Causes

• Handset powered off or out of range.
• Number is a landline.
• Carrier issue.
• Carrier filtering on long codes or toll-free numbers.

Troubleshooting Checklist

• Confirm the device is powered on with signal.
• Cycle the device and retry.
• Verify the device is on its home network (off-network roaming isn't guaranteed).
• Check whether the device receives non-Sparkforge SMS.
• Try a shorter, single-segment message body.
• Test from a different Sparkforge number.

If 30003 keeps repeating on long codes or toll-free numbers, carrier filtering is the likely cause. Collect 3+ examples from the last 24 hours and open a support request.

30004: Recipient Opted Out or DND Enabled

The destination is blocked from receiving the message.

Causes

• Opt-out via STOP keyword.
• DND toggle on the contact's profile.
• Number on India's national Do Not Call registry.
• Toll-free message to a previously opted-out US/CA recipient.

Fix

For India DNC issues or recurring 30004s, collect 3+ examples and contact Support.

30005: Recipient Number Inactive or Doesn't Exist

The destination number is unknown, inactive, or a landline. Verify the number is correct and in E.164 format. For recurring failures, collect 3+ examples and contact Support.

30006: Landline or Unreachable Carrier

The destination can't receive the message — typically a landline or, for short codes, an unreachable carrier.

30007: Message Filtered

Sparkforge or a wireless carrier filtered the message. Filters protect against spam, phishing, fraud, and policy violations.

Causes

• Sparkforge filter flagged the message as spam or unwanted.
• A wireless carrier blocked the message under its rules.

Fixes

• Confirm your messaging use case complies with the Sparkforge Messaging Policy.
• If you believe the filter is wrong, collect 3+ undelivered examples with error 30007 and contact Support.

30008: Unknown Error

Sparkforge received a generic error from a carrier partner with no further detail.

Fixes

• Try a shorter message with simple content and no special characters — this isolates concatenation or encoding issues.
• Open a support request with 3+ examples no older than 48 hours.

30011: MMS Not Supported in This Region

• Inbound: Sparkforge doesn't support incoming MMS in the recipient's region. Reply via SMS to let the sender know.
• Outbound: the destination handset doesn't support MMS or has it disabled.

30023: Daily Message Cap Reached

Your Brand has hit the carrier's daily message limit. The cap applies per EIN across all platforms where the Brand is registered, based on T-Mobile (including Sprint and MetroPCS) outbound SMS segments and MMS. Contact Support.

30032: Toll-Free Number Not Verified

You sent from a US/CA toll-free number that hasn't completed Sparkforge's required verification.

Causes

• Verification not yet submitted.
• Verification submission rejected.

As of November 8, 2023: messages on restricted toll-free numbers are blocked. As of January 31, 2024: messages on pending toll-free numbers are blocked. Complete verification before sending.

21610: Recipient Unsubscribed

The destination opted out via STOP or has DND enabled, so messages are blocked until they re-opt-in with START.

Causes

• Recipient sent STOP or another opt-out keyword.
• Number reassigned to a new user.
• DND toggle on for SMS, calls, or all communication.

Fixes

• Remove the number from the recipient list.
• Ask the recipient to text START to re-opt-in.
• Confirm consent before sending.

30033: A2P 10DLC Campaign Suspended

The sending campaign is suspended. Contact Support for the suspension reason and resolution path.

30037: Outbound Messaging Disabled

The account is configured to block outbound messages. If this is wrong, contact Support.

21612: "To"/"From" Combination Not Allowed

The number combination can't deliver.

Causes

• Number not in E.164 format — Sparkforge auto-standardizes and may reformat unexpectedly.
• Sparkforge has no carrier connectivity to the destination.
• Sender ID restrictions in the destination country.

Fix

Try a different To/From combination or contact Support.

30034: Number Not Fully Registered for A2P Messaging

You tried to send from a newly registered A2P 10DLC number before carrier-level provisioning completed. Brand and campaign approval are not the final step — carrier registration takes up to 24 hours after approval.

Fixes

• Wait 24 hours after A2P approval before sending.
• Don't test during the propagation window.
• Confirm registration in the Trust Center or Phone Number Settings.
• If the issue persists past 24 hours, contact Support with your registration details.

21606: "From" Number Not Valid for This Destination/Account

The sending number isn't a valid SMS sender for the destination or account.

Causes

• Number isn't SMS-capable.
• Number not in E.164 format.
• Short code not registered in the recipient's country.
• Port or host transfer not yet complete.
• Number doesn't belong to the sending account.

Fixes

• Verify SMS capability under Settings → Phone Numbers.
• Confirm E.164 formatting.
• For short codes, confirm the sender and recipient are in the same country.
• For ports, check status under Phone Numbers → Porting Requests.