Either when an error occurs or when a response is successful, the response body usually contains return codes as shown:
| Return code | Description |
| 0 | Success |
| 1 | Parameter error, indicating that the number and type of parameters are incorrect |
| 2 | Data check failed (MAC mismatch) |
| 3 | Data format error |
| 4 | Processing failed |
| 5 | Invalid access token |
| 6 | Access token has expired |
| 7 | Invalid request type |
| 8 | Invalid APP version |
| 9 | User does not exist |
| 10 | Invalid real name |
| 11 | Invalid email |
| 12 | Registration authorization code format error |
| 13 | Bad password format |
| 14 | Failed to send registration authorization code email |
| 15 | Invalid authorization code |
| 16 | Already registered |
| 17 | Registration failed |
| 18 | User is not registered |
| 19 | User registration is not activated |
| 20 | User account is closed |
| 21 | Login failed |
| 22 | Wrong password |
| 23 | Document information error or invalid |
| 24 | Document page does not exist |
| 25 | Document page’s image does not exist |
| 26 | Signature picture does not exist |
| 27 | The recipient does not exist |
| 28 | No signature needed |
| 29 | Signing failed |
| 30 | User is locked |
| 31 | Adding a face user failed |
| 35 | SMS verification failed |
| 36 | Document creation failed |
| 37 | Failed to delete unsigned document |
| 38 | Failed to delete unsigned document(s) |
| 39 | Sending reminder email failed |
| 40 | Failed to add document |
| 41 | Document does not exist |
| 42 | Document does not belong to this user |
| 43 | Report does not exist |
| 44 | Illegal operation |
| 45 | Send mail failed |
| 46 | Invalid API type |
| 47 | Account does not exist |
| 48 | Authorized |
| 49 | Mailbox belongs to another account |
| 50 | Non-admin account |
| 51 | Unauthorized |
| 52 | Default role does not exist |
| 53 | Integration key does not exist |
| 54 | Data decryption failed |
| 55 | Signature picture does not exist |
| 56 | System type error |
| 57 | Version does not exist |
| 58 | No push terminal, please log in to your APP |
| 59 | Requires signature verification |
| 60 | Failed to send SMS |
| 61 | Push authentication refused |
| 62 | Authentication response timed out |
| 63 | New password cannot same with old password |
| 64 | Phone token registration failed |
| 65 | Phone number is empty, this operation cannot be performed |
| 66 | Your verification failed multiple times and has been locked. Please contact the document creator to resend your signing request |
| 67 | Signature failed, personal ID number cannot be blank |
| 68 | Signature failed, corporate ID number cannot be empty |
| 69 | Failed to add document template |
| 70 | Add document template name already exists |
| 71 | Document does not exist |
| 72 | Data length does not match |
| 73 | Document number already exists |
| 74 | Insufficient account credit |
| 75 | Signatories reached the limit |
| 76 | HTML format is incorrect |
| 77 | Number of templates reached limit |
| 78 | This signatory has signed this document |
| 79 | The signer has signed, and the send verification failed |
| 80 | The template name is invalid. |
| 81 | Illegal document number, only allow letters, numbers and @_,- |
| 82 | Personal or business type error, matching numbers |
| 83 | Bad document type, matching numbers |
| 84 | Wrong name, matching characters, letters, numbers, “.-_ @” |
| 85 | Bad ID number type |
| 86 | Incorrect phone number type |
| 87 | Invalid image data |
| 88 | Template does not exist |
| 89 | The system is busy |
| 90 | This account does not support LTV |
| 91 | Document validation failed |
| 92 | File types do not match |
| 93 | Upload file size too big |
| 94 | Template unreview |
| 95 | Location not set or occupied |
| 96 | Document has been completed |
| 97 | Verification code expired |
| 98 | Template failed |
| 99 | Account does not support SMS |
| 100 | No valid certificate exists |
| 101 | Certificate issue failed |
| 102 | Certificate revocation failed |
| 103 | Please upload valid documents types |
| 104 | Signature or signature picture size is invalid |
| 105 | Insufficient SMS account balance |
| 106 | Timestamp error |
| 107 | Document has been signed but deleted |
| 108 | Mobile OTP failed with maximum attempt (5 times) |
| 109 | Mobile OTP authentication failed |
| 110 | EKYC is failed |
| 111 | Contract expired |
| 112 | Diskspace exceed |
| 113 | Cannot apply ECA and DSA in a same document |
| 114 | Cannot apply different DSA in a same document if account holder purchased DSA based on number of legal document (only existing client in Version 1) |
| 115 | No DSA credit |
| 2001 | Invalid base64 ID document front image |
| 2002 | Invalid base64 ID document front flash image |
| 2003 | Invalid base64 ID document back image |
| 2004 | Invalid selfie image |
| 2005 | File process failed |
| 2006 | Landmark error |
| 2007 | Invalid value |
| 2008 | Unable to retrieve full name |
| 2009 | Unable to retrieve ID number |
| 2010 | Unable to retrieve address |
| 2011 | Unable to retrieve country code |
| 2012 | Unable to retrieve country name |
| 2013 | Unable to retrieve nationality |
| 2014 | Unable to retrieve gender |
| 2015 | Retrieve full name and registered full name does not match |
| 2016 | Landmark failed on color mode |
| 2017 | Landmark failed on microprint |
| 2018 | Landmark failed on hologram |
| 2019 | Landmark failed on substitution image |
| 2020 | Landmark failed on ghost photo detection |
| 2021 | Landmark failed on screen |
| 2022 | Landmark failed on ID brightness |
| 2023 | Landmark failed on face brightness |
| 2024 | Landmark failed on font |
| 2025 | Landmark failed on ID blurriness |
| 2026 | Image size exceeded |
| 2027 | Landmarks record empty |
| 2028 | Wrong document type |
| 2029 | eKYC credit is 0 |