A 470 Error means the message failed to send because more than 24 hours have passed since the customer last replied to this number. To re-initiate a conversation with this error you have to send a template message. That’s because the error means that 24 hours have passed since you last received a user initiated message – the session is closed and you can no longer use free-form messages. If you attempt to send Free-form text messages and media messages outside of the 24h-window, this will result in a failure callback with error 470. You can read more about error scenarios in our documentation.