Are some of your SMS alerts failing? If you select either the red "Failed to send alert" message in the Waitlist view, or the "Failed to send SMS" message that is displayed in the Chat area, it will open up a Message Details box which will provide additional information about the message including a brief description of the error.

If a red error message is displayed (like in the above screenshot) you should be able to match that message to one on our Error Codes and Messages lists found below, which will provide a more detailed description of the error to assist you in troubleshooting the issue.

Error Codes and Messages

Provider: Bandwidth (within the US)

Error Code

Error Message

Description

4700

Carrier Rejected as Invalid Service Type

Carrier rejected message for invalid service type. This usually means messaging (SMS or MMS) is not supported by the carrier or handset.

4720

Carrier Rejected as Invalid Destination Address

Carrier Rejected as Invalid Destination Address. This could mean the number is not in the numbering plan (area code does not exist or the number is just invalid) or the number is not enabled for messaging (like a landline). Additionally, for toll free messages to TMobile, this could also mean the user has opted to block all toll free and short code traffic

4750

Carrier Rejected Message

Carrier Rejected as Invalid Destination Address. This could mean the number is not in the numbering plan (area code does not exist or the number is just invalid) or the number is not enabled for messaging (like a landline). Additionally, for toll free messages to TMobile, this could also mean the user has opted to block all toll free and short code traffic

4770

Carrier Rejected as SPAM

The Carrier is reporting this message as blocked for SPAM. Spam blocks could be a result of content, SHAFT violations (including specific keywords), originating address has been flagged for repeated spam content

4406

Unallocated to number

The To number associated with this message, while a valid North American number, is not yet assigned to a carrier and the message cannot be sent downstream.

4470

Rejected as spam (future)

This message has been filtered and blocked by a downstream carrier for spam. Messages can be blocked for a variety of reason, including but not limited to volumetric filtering, content blocking, SHAFT violation, A2P

5650

Carrier Service Failure

Carrier Service is reporting a failure to send to destination (mobile operator or handset).

4434

Messaging to Toll Free Number Forbidden

Messaging to this toll free number is not allowed. Number is likely not enabled for messaging or not active.

9999

Unknown error from downstream. Carrier reported a failure code that is unknown to Bandwidth.

Bandwidth does not recognize the vendor's error response or does not have the vendor code mapped internally

4730

No route to destination carrier or no roaming route exists.

Carrier is reporting there is no route available for message. This could be because no routing exists to destination, no roaming route is available, the destination handset is roaming on a network that cannot be reached, no SS7 route, or routing was denied

5620

Carrier Application Error

The carrier is reporting a general error associated with their application processing the message.

4740

Carrier Rejected as Invalid Source Address

Carrier is rejecting the message due to invalid source address - the number does not exist in the numbering plan. Other reasons for this error code is the source carrier is invalid or disabled or source not authorized or the number type is not supported.

4775

Carrier Rejected due to user opt out

User has opted out of receiving messages from a particular sender. Remove the destination TN from subscriber list and cease communication with the destination.

5106

Impossible-to-route

Impossible to route / Attempt to deliver through retries has failed.

4432

Messaging to country forbidden

Bandwidth system indicates the account associated with the message is not enabled for messaging this zone, this country or this country is outside of messaging reach (specifically for MMS).

4405

Unallocated from number

The From telephone number is considered unallocated when the number does not exist in our database as an active number. This number is either not enabled for messaging at the industry level, or the number is not yet released in the industry

5999

Unknown error from downstream

Unknown error generated by Bandwidth when Bandwidth core reports an unknown error

These are the most commonly displayed SMS error messages. If the error message you are seeing is not listed, you can find a more extensive list of Bandwidth error messages and descriptions here.

Provider: Twilio (outside of the US)

Error Code

Error Message

Description

30003

Message Delivery - Unreachable destination handset

The carrier for the phone number Waitwhile is trying to send the message to is reporting the 'To' number is unreachable - the device is likely powered down, out of the service area, or may not accept your messages.

30005

Message Delivery - Unknown destination handset

The carrier for the phone number Waitwhile is trying to send the message to is reporting the To number is unknown or no longer in service.

30007

Message Delivery - Carrier violation

The carrier for the phone number Waitwhile is trying to send the message to is filtering out your messages for delivery (possibly due to being flagged as spam).

30008

Message Delivery - Unknown error

The carrier for the phone number Waitwhile is trying to send the message to returned a generic error message.

21614

To' number is not a valid mobile number

You have attempted to send a SMS with a 'To' number that is not a valid mobile number. It is likely that the number that you have specified is a landline number or is an invalid number.

30006

Message Delivery - Landline or unreachable carrier

The carrier for the phone number Waitwhile is trying to send the message to is a landline phone or the carrier can't be reached.

21211

Invalid 'To' Phone Number

You attempted to send an SMS to a number that was either formatted incorrectly or was not a valid phone number.

21408

Permission to send an SMS or MMS has not been enabled for the region indicated by the 'To' number

You have attempted to send an SMS to a region that has not been enabled for SMS by Waitwhile.

30004

Message Delivery - Message blocked

Your message has been blocked from reaching the guests phone.

21612

The 'To' phone number is not currently reachable via SMS

The carrier Waitwhile is trying to send the message to is not a supported carrier.

21610

Message cannot be sent to the 'To' number because the customer has replied with STOP

Waitwhile is attempting to send a message to a number that has opted out of receiving messages using a STOP keyword.

These are the most commonly displayed SMS error messages. If the error message you are seeing is not listed, you can find a more extensive list of Twilio error messages and descriptions here.

Reporting SMS Issues to Waitwhile Support

In the event that a large amount of SMS are failing unexpectedly with the same error message, or the error message displayed seems incorrect, please reach out to Waitwhile support and if possible include Message IDs (or screenshots of the Message Details box) for a few of the failed messages so that we can reach out directly to our SMS providers for additional assistance.

Have you exceeded your SMS limit for the billing period?

Each subscription plan has an allotted total number of SMS messages that can be sent during each billing period, as well as a separate limit on how many messages can be sent to an individual customer per visit.

The limit of SMS per visit is typically 8 messages (though this number may be higher for certain subscription plans). In the event that a customer has rescheduled a booking, it will still count as the same visit, potentially causing the per visit SMS limit to be reached. If this occurs, you could cancel the original booking and create a new one for the rescheduled date so that the SMS messages will not count against the original per visit message quota (though the new visit will count against your overall visit allotment for the period).

If you have used all of your total allotted messages for the billing period, we recommend upgrading to a higher subscription plan.

Related Articles:

Best Practices: Making Sure Your Messages Don't Get Blocked by Cell Carriers

How to Use SMS Reply Triggers

FAQ: Why is "Reply STOP" being added to confirmation texts?


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