title: Reserved, Invalid, and Misconfigured Usernames created at: Thu Oct 31 2024 08:17:32 GMT+0000 (Coordinated Universal Time) updated at: Sat Feb 08 2025 14:22:50 GMT+0000 (Coordinated Universal Time) --- # Reserved, Invalid, and Misconfigured Usernames # Overview This document explains cPanel & WHM’s username restrictions and what to do if you encounter an invalid, reserved, or misconfigured username. # Basic restrictions cPanel & WHM applies the following rules when you create or modify a cPanel or WHM username: Usernames may **only** use lowercase letters (`a–z`) and digits (`0–9`). * Usernames **cannot** contain more than 16 characters. * Usernames **cannot** begin with a digit (`0–9`) or the string `test`. * Usernames **cannot** end with the string `assword`. ## Special cases * You **cannot** create a username with the hyphen character (`-`), but you can change an account’s name to use a hyphen when you transfer that account to another system. * To allow usernames over eight characters in length, set the `LONGUSERS: 1` environment variable in the `/var/cpanel/whm/nvdata/root.yaml` file. * If you plan to use MySQL or PostgreSQL as a database engine, the first eight characters **must** be unique on the system. !! Note:\ You can disable database prefixing with the *Add prefix to names of new databases and database users* option in the SQL section of WHM’s [*Tweak Settings*](https://docs.cpanel.net/whm/server-configuration/tweak-settings/) interface (*WHM » Home » Server Configuration » Tweak Settings*). * To allow leading digits in a username, create the `/etc/allowstupidstuff` touch file. # Reserved usernames !! Important: !! During [TSR-2017-0006](https://news.cpanel.com/cpanel-tsr-2017-0006-full-disclosure/) , we expanded the list of reserved usernames to include email aliases listed in the `/etc/aliases` and `/etc/localaliases` files. The system will also reserve usernames that are aliased to a reserved username. cPanel & WHM reserves some usernames for the system’s use, and you cannot use them for cPanel or WHM accounts. This list of reserved usernames can grow over time, and new versions of cPanel & WHM may add to this list. cPanel & WHM checks the following files to determine whether to reserve or restrict a username or alias: * `/usr/local/cpanel/Cpanel/Validate/Username/Core.pm` * `/etc/aliases` * `/etc/localaliases` ## Reserved aliases By default, the system reserves the following list of aliases: | Username | Alias | | ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `root` | `abuse, adm, amandabackup, apache, bin, canna, daemon, dbus, decode, desktop, dovecot, dumper, fax, ftp, games, gdm, gopher, halt, hostmaster, ident, ingres, ldap, lp, mail, mailnull, manager, mysql, named, netdump, news, nfsnobody, nobody, noc, nscd, ntp, nut, operator, pcap, postfix, postgres, postmaster, privoxy, pvm, quagga, radiusd, radvd, root, rpc, rpcuser, rpm, security, shutdown, smmsp, squid, sshd, sync, system, toor, uucp, vcsa, webalizer, webmaster, wnn, xfs` | | `postmaster` | `info, mailer-daemon, marketing, sales, support` | | `news` | `newsadm, newsadmin, usenet` | | `ftp` | `ftp-adm, ftp-admin, ftpadm, ftpadmin` | | `webmaster` | `www` | # Resolve problems To resolve issues with invalid, reserved, or restricted usernames or aliases, run the following command as the `root` user to rename the account: ```bash whmapi1 modifyacct user=username newuser=newusername ``` !! Note: !! In this example, `username` represents the current (restricted) username, and `newusername` represents the new username that you wish to assign to the account. ## Remove username aliases You can also remove reserved aliases from the `/etc/aliases` and `/etc/localaliases` files. ## Misconfigured usernames Misconfigured usernames do not possess some information or exist in an incomplete state. To fix a misconfigured username, run the following command as the `root` user: ```bash /usr/local/cpanel/scripts/updateuserdomains --force ```