--- "@context": https://schema.org "@type": TechArticle "@id": https://www.twilio.com/docs/smpp/error-codes#article headline: Error Codes description: Discover common Twilio SMPP API error codes to troubleshoot SMS issues like connection errors and message rejections effectively. url: https://www.twilio.com/docs/smpp/error-codes inLanguage: en dateModified: 2026-07-21T11:17:13.000Z author: "@type": Organization name: Twilio Developer Education Team publisher: "@type": Organization name: Twilio --- # Error Codes Twilio SMPP API error codes indicate problems that occur during SMS message processing, such as connection errors or message rejections. When a request fails, Twilio returns the corresponding error code to help you troubleshoot. The common error codes are listed in the following table. To learn more about SMS error codes, see [Error and Warning Dictionary](/docs/api/errors). | Code | Description | | ---- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 000 | No error. | | 001 | Absent subscriber. The HLR responded to the SRI for SM request with an error indicating the subscriber is absent. | | 002 | Handset memory capacity exceeded. Handset has run out of free memory to store new message. | | 003 | Equipment protocol error. | | 004 | Equipment not equipped with short-message capability. | | 005 | Unknown subscriber. The IMSI is unknown in the HLR. The HLR responded to the SRI for SM request with an error indicating the subscriber is unknown. | | 006 | Illegal subscriber. The mobile station failed authentication. | | 007 | Teleservice not provisioned. Message is rejected because the recipient MS (Mobile Subscriber) has no SMS subscription. | | 008 | Illegal equipment. IMEI check failed, i.e. The IMEI is either blacklisted or not whitelisted. | | 009 | Call barred. Operator barred the MSISDN number. | | 010 | Facility not supported. VLR in the PLMN does not support MT short message service. | | 011 | Subscriber busy for MT short message. | | 012 | System failure. Task cannot be completed because of a problem in another entity. | | 013 | Data missing. Necessary parameter is not present in the primitive. | | 014 | Unexpected data value. The provided data is incorrectly formatted in the primitive. | | 015 | Unidentified subscriber. Subscriber isn't in the database, and the system can't determine whether a subscription exists. | | 016 | Absent subscriber. No paging response via MSC. | | 017 | Absent subscriber. IMSI detached. | | 018 | Absent subscriber. Roaming restriction. | | 020 | Mobile subscriber not reachable. | | 021 | Local cancel - No response for the SRI for SM request was received. | | 047 | TCAP error. | | 049 | SMS discarded. This error is specific to IP-based protocols like SMPP. | | 050 | SMS window exceeded. | | 051 | SMS malformed. SMS is not formed correctly. This error is specific to IP-based protocols like SMPP. | | 052 | SMS expired. | | 053 | Insufficient credit. The user has insufficient credit or doesn't have permission to send to the specified destination. | | 054 | Invalid destination. Receiver is not a valid number. | | 055 | Unable to find outbound route for this SMS. | | 056 | SMS buffered. | | 057 | Timeout waiting for response from peer. | | 058 | Throttling Error. The user has exceeded allowed message limit. | | 059 | Absent subscriber: The message is undeliverable because the subscriber is temporarily unavailable, e.g. their phone is switched off or they cannot be located on the network. | | 060 | Portability error: The message failed because the ported number combinations were unreachable. | | 061 | Invalid PDU Format. | | 062 | ESME Client Error. | | 063 | Local ACL Deny. | | 064 | Invalid Payload Length. | | 065 | Remote Logic Error. | | 066 | Remote Logic Deny. | | 067 | DCS inconsistency. | | 068 | Routing error. | | 069 | Rejected - SMSC rejected the SRI for SM request. | | 070 | PSA Connection failed. | | 162 | Abort - The HLR (or some other entity in the network) aborted the SRI for SM request. | | 205 | Illegal subscriber. | | 206 | Illegal equipment. | | 218 | Screening error, Terminating IMSI blocked. | | 255 | Unknown error. | | 711 | Destination network or country is blocked. Contact Twilio customer support to unblock this network/country. | | 712 | Insufficient credits to send message. | | 713 | SMS sent, no delivery report received. | | 714 | Route loop detected. | | 716 | Flood protection – Multiple identical messages to Recipient detected. | | 717 | Invalid srcAddr. | | 718 | Invalid msisdn/destAddr. | | 800 | The end user does not exist. | | 801 | The end user is blocked. | | 802 | The end user belongs to a network operator that does not allow charge. | | 803 | The end user is not allowed to purchase premium services. | | 826 | Message body error. | | 828 | Message too long. | | 925 | Operator network failure. | | 928 | Blocked due to spam. |