Handling High Volume SMS Errors

Last updated: 2022-03-02Contributors
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High Volume SMS provides detailed error codes for reasons why a SMS may have failed sending or delivery which can be used to determine how to adjust your campaigns.

Error Code Structure

Error codes are composed of a prefix and a number. The prefix identifies the error reporting party and the numeric code is aligned with HTTP response status codes. In the following error code, SMS-CAR-411, SMS-CAR- is the prefix and 411 is the numeric code.

Error Reporting Party Prefix

For SMS, there are 3 parties that can return an error:

Party Error Code Prefix Description
RingCentral  SMS-RC- RingCentral's own error checking.
Upstream Provider SMS-UP- This is the upstream sending carrier.
Recipient's Carrier SMS-CAR- This is the recipient's wireless provider.

Error / Status Numbers

The numerical portion of the error follows a subset of HTTP status conventions:

  1. Informational responses (100–199)
  2. Client errors (400–499)
  3. Server errors (500–599)

Common Errors

Commonly encountered errors fall into categories:

  1. Sending to invalid numbers such as landline numbers or other numbers that cannot support texting.
  2. Being rejected as spam.

Invalid Number

When you receive an error that indicates a number is invalid or unavailable (e.g. SMS-UP-410, SMS-UP-411, SMS-UP-412, SMS-UP-413), you should make a note of it and consider stopping messages to that number. You can also ask your user to confirm the validity of their number (via SMS) before resuming messages.

A common reason for this is texting to landline numbers that do not have texting capability. An API service like NumVerify can be used to check whether a number is a landline number (without texting capability) or a mobile number (likely with texting capability).


If are receiving a lot of spam rejections, your users may be indicating this is spam or the carrier may be using spam detection algorithms. In this case, you should consider changing your message so it is not recognized as spam. After you change your message, you may want to consider provisioning a new phone number with the updated messages as your existing number may be blacklisted.

Different recipient wireless carriers will have different spam policies so it may be worthwhile to check errors against recipient carrier. An API service like NumVerify can also be used to identify the recipient's wireless carrier.

Expected Errors

Some information is provided for informational purposes and while it may be classified as an error, may be expected from carriers. For example, it may not possible to get delivery status from carriers as reported by SMS-CAR-104 and SMS-CAR-199. When checking for delivery success and failure, you may want to verify receipt of the SMS message before classifying these as non-delivered.s

Error Code List

Code Description
SMS-UP-410  Destination number is invalid, unallocated, or does not support this kind of messaging.
SMS-UP-430 This message has been filtered and blocked by a upstream carrier for spam.
SMS-UP-431  From number is blacklisted due to spam or other violations.
SMS-UP-500  General upstream error. Upstream is malfunctioning.
SMS-CAR-104  Carrier has not reported delivery status.
SMS-CAR-199  Carrier reports unknown message status.
SMS-CAR-400  Carrier does not support this kind of messaging.
SMS-CAR-411  Destination number invalid, unallocated, or does not support this kind of messaging.
SMS-CAR-412  Destination subscriber unavailable.
SMS-CAR-413  Destination subscriber opted out.
SMS-CAR-430  This message has been filtered and blocked by a recipient's carrier for spam.
SMS-CAR-431  Message rejected by carrier with no specific reason.
SMS-CAR-432  Message too long.
SMS-CAR-433  Message is malformed for the carrier.
SMS-CAR-450  P2P messaging volume violation. Please contact RingCentral support to review your account settings and ensure you are utilizing the appropriate A2P provisioning for high volume traffic
SMS-CAR-460  Destination rejected short code messaging. Currently not applicable for RingCentral.
SMS-CAR-500  Carrier reports general service failure.
SMS-RC-410  Destination number unsupported.
SMS-RC-413  Destination subscriber opted out.
SMS-RC-430 This message has been filtered and blocked by a RingCentral's message filtering system for spam.
SMS-RC-500  General/Unknown internal RC error.
SMS-RC-501 RingCentral is sending an invalid upstream API call. Please raise a support ticket with RingCentral developer support.
SMS-RC-503 RingCentral provisioning error. Phone number is incorrectly provisioned by RingCentral in upstream.