| Code | Explanation |
| 100 | The requested action is being initiated, expect another reply before proceeding with a new command. |
| 110 | Restart marker replay . In this case, the text is exact and not left to the particular implementation; it must read: MARK yyyy = mmmm where yyyy is User-process data stream marker, and mmmm server’s equivalent marker (note the spaces between markers and “=”). |
| 125 | Data connection already open; transfer starting. |
| 150 | File status okay; about to open data connection. |
| 200 | The requested action has been successfully completed. |
| 202 | Command not implemented, superfluous at this site. |
| 211 | System status, or system help reply. |
| 212 | Directory status. |
| 213 | File status. |
| 214 | Help message. Explains how to use the server or the meaning of a particular non-standard command. This reply is useful only to the human user. |
| 215 | NAME system type. Where NAME is an official system name from the registry kept by IANA. |
| 220 | Service ready for new user. |
| 221 | Service closing control connection. |
| 225 | Data connection open; no transfer in progress. |
| 226 | Closing data connection. Requested file action successful (for example, file transfer or file abort). |
| 227 | Entering Passive Mode |
| 228 | Entering Long Passive Mode (long address, port). |
| 229 | Entering Extended Passive Mode (|||port|). |
| 230 | User logged in, proceed. Logged out if appropriate. |
| 231 | User logged out; service terminated. |
| 232 | Logout command noted, will complete when transfer done. |
| 234 | Specifies that the server accepts the authentication mechanism specified by the client, and the exchange of security data is complete. A higher level nonstandard code created by Microsoft. |
| 250 | Requested file action okay, completed. |
| 257 | “PATHNAME” created. |
| 300 | The command has been accepted, but the requested action is on hold, pending receipt of further information. |
| 331 | User name okay, need password. |
| 332 | Need account for login. |
| 350 | Requested file action pending further information |
| 400 | The command was not accepted and the requested action did not take place, but the error condition is temporary and the action may be requested again. |
| 421 | Service not available, closing control connection. This may be a reply to any command if the service knows it must shut down. |
| 425 | Can’t open data connection. |
| 426 | Connection closed; transfer aborted. |
| 430 | Invalid username or password |
| 434 | Requested host unavailable. |
| 450 | Requested file action not taken. |
| 451 | Requested action aborted. Local error in processing. |
| 452 | Requested action not taken. Insufficient storage space in system.File unavailable (e.g., file busy). |
| 500 | Syntax error, command unrecognized and the requested action did not take place. This may include errors such as command line too long. |
| 501 | Syntax error in parameters or arguments. |
| 502 | Command not implemented. |
| 503 | Bad sequence of commands. |
| 504 | Command not implemented for that parameter. |
| 530 | Not logged in. |
| 532 | Need account for storing files. |
| 534 | Could Not Connect to Server – Policy Requires SSL |
| 550 | Requested action not taken. File unavailable (e.g., file not found, no access). |
| 551 | Requested action aborted. Page type unknown. |
| 552 | Requested file action aborted. Exceeded storage allocation (for current directory or dataset). |
| 553 | Requested action not taken. File name not allowed. |
FTP/FTPeS command line error codes and their meaning
Updated on June 13, 2025