Understanding WhatsApp Campaign error codes and failure reasons

Updated January 30, 2026 · 3 minute read

When running high-volume WhatsApp campaigns via the API (in ZEPIC), you may occasionally encounter failures. However, error codes help you understand them!

WhatsApp errors fall into several categories: those related to the recipient, those related to content/templates, those about throttling/limits, and those related to your account status.

Quick resolution of failure reasons guarantees higher deliverability, improved message quality scores, and protects your account from restrictions.

Common failure reasons and solutions

The following table lists the most frequently encountered failure reasons in a WhatsApp campaign on ZEPIC and their recommended troubleshooting steps

Error Code / Reason Category	Meaning (Why it Failed)	Action (How to Fix)
131026 / Message Undeliverable	Recipient's number is not a valid WhatsApp account, they haven't accepted the latest Terms of Service, or they are using an outdated app version.	Remove invalid numbers from your lists. Prompt the customer via email/SMS to update their app and accept the latest T&Cs.
131047 / Re-engagement Window Expired	You attempted to send a regular, free "session message" more than 24 hours after the customer's last reply.	Immediately switch to a pre-approved Template Message (HSM) to initiate a new conversation outside the 24-hour window.
131008 / Blocked by User	The customer has explicitly blocked your WhatsApp Business number.	Stop all attempts to message this user immediately. Continuing can severely damage your quality rating. Review your consent process.
131049 / Message Blocked (Ecosystem Protection)	Meta chose not to deliver the message to protect the user from unsolicited or low-quality content, often due to high block/report rates or hitting per-user marketing limits.	Do not retry immediately. Improve message quality, target only users with strong opt-in, and retry using ZEPIC's Smart Retries feature with increasing time gaps.
131048 / Spam Rate Limit Hit	Your business number has exceeded its overall messaging limit or is restricted due to previous policy violations or high user reporting.	Check your Quality Status in WhatsApp Manager. Reduce the volume/frequency of messages sent. Focus entirely on sending high-quality, high-engagement content to raise your rating.
131042 / Business Eligibility / Payment Issue	Your WhatsApp Business Account has billing issues (e.g., credit line exceeded, payment method invalid) in Meta Business Manager.	Log in to Meta Business Manager and resolve any outstanding invoices or payment method issues immediately.
132001 / Template Does Not Exist	The Template Message name/language code you are trying to use in the API call is incorrect, or the template is not yet approved.	Verify that the exact name and language code used in the ZEPIC campaign setup match the approved template in the Templates section. Wait for Meta approval.

General troubleshooting steps

For any failure reason, follow these universal steps:

Check quality status: Always monitor your phone number's quality rating (Green, Yellow, Red) in the WhatsApp Manager. A "Yellow" or "Red" status requires immediate action to reduce volume and improve content.
Verify number format: Ensure all recipient numbers are in the correct E.164 format (Country Code + Full Number, e.g., +919876543210). Invalid formats are a frequent cause of the 131026 error.
Use Smart Retries: For temporary failures like "Device Offline," rely on ZEPIC's Smart Retries feature to automatically attempt delivery at optimal intervals.
Contact ZEPIC support: If the error is generic (e.g., 500 Internal Server Error) or persists after troubleshooting, contact your ZEPIC support team for assistance with Meta API diagnostics.

Do you need help improving your current WhatsApp quality score? We have an article that covers that!