# SMS Delivery Report Error Codes

Delivery reports track the status of SMS messages from Airship's third-party providers to your audience and may contain an `error_code` to describe why your message was not delivered.
Airship's standard error codes for the most common errors encountered:

| Error code | Description |
| --- | ---- |
| 0   | Unknown error |
| 10  | Landline or unreachable carrier |
| 16  | Message blocked |
| 61  | Message filtered |
| 64  | Error, blocked due to exceeded quota |
| 150 | Unknown destination handset |
| 152 | Numeric Sender ID Not Provisioned on Carrier |
| 300 | Unreachable destination handset |

Some codes aren't necessarily errors and indicate that a message has not yet been delivered, most notably `400` (queued) and `401` (dispatched).

The following example shows one of many `error_code` values relevant to SMS delivery report events:

**Example SMS Delivery Report**

```json
{
  "body": {
    "interaction_type": "delivery_report",
    "name": "dispatched",
    "properties": {
      "error_code": "401",
      "sender": 18587323362,
      "vendor": "CLX",
      "vendorDeliveryId": "ZLOiTjmZfV6r0-Eo"
    },
    "source": "API",
    "triggering_push": {
      "push_id": "7764f7bd-a206-4219-9933-a9bcb7dc9979"
    }
  },
  "device": {
    "channel": "73c29b53-a00a-4567-9ccd-1d726013699d",
    "delivery_address": "19712754475",
    "device_type": "SMS",
    "identifiers": {
      "sender": "18587323362"
    }
  },
  "id": "0f7d521f-dc6c-4530-9623-91fb8d370db5",
  "occurred": "2020-06-01T18:26:12.575Z",
  "offset": "1000032182771",
  "processed": "2020-06-01T18:26:13.558Z",
  "type": "CUSTOM"
}
```


In addition to these common errors, other errors might be returned, depending on your delivery service provider, Sinch or Twilio. Review the following sections relevant to your service provider to determine the meanings of error codes.

## Sinch (CLX) Error Codes

Sinch was formerly known as CLX. For all `error_code` values that apply when a delivery report's `vendor` property is `CLX`, see [Message Error Specification](https://developers.sinch.com/docs/sms/other/sms-other-http-basic/#message-error-specification) in Sinch's *HTTP Basic for SMS* documentation.

### Sinch (CLX) MMS Result/Error Codes

The following `error_code` and `report_code` values are most common and relevant for MMS messages when a delivery report's `vendor` property is `CLX`:

| Error or report code | Description |
| --- | --- |
| N101 | Message Sent |
| N102 | Message Sent/Delivered |
| E101 | Message Failed |
| E102 | Message Sent/Expired, Sent/Rejected, Sent/Failed or, Sent/Not Supported |

For all Sinch MMS error codes, see [](https://developers.sinch.com/docs/mms/xml-service/appendix/) in Sinch's *XML Service Appendix*.

## Twilio Error Codes

For `error_code` values that apply when a delivery report's `vendor` property is `TWILIO`, see Twilio's [Error and Warning Dictionary](https://www.twilio.com/docs/api/errors).