FTP Server Return Codes – 1nn to 500

FTP codes are numerical codes used by an FTP server to indicate the status or result of a given request. They describe different errors that may occur with a request, allowing the user to adjust or take the correct action. Below is a list of the most common FTP server return codes.

How do FTP server return codes work?

Initially, the FTP (File Transfer Protocol) server return codes are sent from the FTP server to the requesting device. This is done to let the requesting device know where the connection stands. Then, the File Transfer Protocol server relays to the requesting device where the connection process is and what to do next.

Each FTP server return code is three digits long. The first digit shows whether the response is okay, not okay, or incomplete. The second digit represents function grouping. Finally, the third digit gives a more specific meaning of the function group specified in the second digit.

Take, for example, the common list of FTP server return codes below. They each contain three characters or digits, following the functions listed above.

The 200 series indicates that the requested action was successfully completed.

The 300 series indicates that the command was accepted, but the requested action was put on hold temporarily.

The 400 series indicates that the command was rejected and the requested action did not take place, but the error isn’t permanent.

The 500 series indicates that there was a syntax error. The device does not recognize the command and the requested action did not take place.

For a master list of FTP codes and FTP commands, please visit The Internet Engineering Task Force (IETF®). They are responsible for setting and maintaining the FTP response codes.

FTP server return codes on a device

FTP server return codes

1nn Server Return Codes

1nn -  Initiation of requested action; expect another reply before proceeding with a new command.

2nn - Command accepted; requested action successfully completed.

3nn - Command accepted, but the action needs a receipt of further information

4nn - Command has been denied on a temporary basis

5nn - Command has been denied on a permanent basis; permanent negative completion reply

n0n Server Return Codes

n0n - Syntax

n1n - Information

n2n - Connection

n3n - Authentication

n4n - Not Specified

n5n - File System

150 - File status okay

200 Server Return Codes

200 - Command okay

202 - Command not implemented

211 – System status

212 – Directory status

213 – File status

214 – Help message

220 – Service ready for new user

221 – QUIT command received

225 – Data connection open

226 – Closing data connection

227 – Entering passive mode

229 – Entering extended passive mode

230 – User logged in

234 – Security data exchange complete

250 – Requested file action okay

300 Server Return Codes

331 - Username okay, need password

332 - Need account for login

400 Server Return Codes

421 – Service not available, closing control connection (most likely temporary)

425 – Can't open data connection

426 – Connection closed, transfer aborted

431 – Temporarily can’t process security

450 – File busy, SFS directory unavailable

452 – Insufficient storage space

451 – Local error in processing

500 Server Return Codes

500 - Syntax error, command unrecognized

501 - Syntax error in parameters or arguments

502 - Command not implemented

503 - Bad sequence of commands

504 – Command not implemented for parameter

521 – Data connection can’t be opened with settings

522 – Unsupported protocol

530 – User not logged in

532 – Need account for file storage

533 – Command protection level denied for policy

550 – Action not taken; file not found

551 – Action aborted; page type unknown

553 – Action not taken; file name forbidden