Marichi Talks
A message WhatsApp could not deliver, returned with an error explaining why, such as an invalid number or a closed reply window.
A failed message is one that did not reach the customer. WhatsApp returns an error code with a reason. Common causes: the number is not on WhatsApp, a free-form reply was sent after the customer service window closed, the template was paused or not approved, your messaging limit was reached, the customer has received too many marketing messages from businesses recently, or there was a problem with media.
Failures cost you reach and, if nobody looks, they hide real problems such as a broken template or a list full of landline numbers.
Read failure reasons in groups, not one by one. Remove numbers that are not on WhatsApp, fix templates that fail, and use a template instead of free text when the window has closed. For critical messages, such as one-time codes, plan a fallback channel like SMS. Campaign reports in Marichi Talks show failed counts so these are visible.