A user in the system needs to be deleted if it's no longer needed, such as when the associated person resigns from a job. If the person is only changing roles, it's better to change the group for the user instead of deleting and creating a new user.

Related: How to add user to group in Linux
Related: How to remove user from groups in Linux

A local user is deleted by removing appropriate entries in user and group related files such as /etc/passwd, /etc/group, and /etc/shadow. These entries can either be removed manually or by using specialized tools such as userdel.

Using such a tool is always the better option as it reduces errors. When deleting the user, you can also delete files and folders owned by the user, such as the home directory.

Steps to delete user in Linux:

  1. Launch terminal.
  2. Get the list of users for your system. 

    $ getent passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin bin:x:2:2:bin:/bin:/usr/sbin/nologin sys:x:3:3:sys:/dev:/usr/sbin/nologin sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/usr/sbin/nologin man:x:6:12:man:/var/cache/man:/usr/sbin/nologin lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin mail:x:8:8:mail:/var/mail:/usr/sbin/nologin news:x:9:9:news:/var/spool/news:/usr/sbin/nologin uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin proxy:x:13:13:proxy:/bin:/usr/sbin/nologin www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin backup:x:34:34:backup:/var/backups:/usr/sbin/nologin list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin systemd-timesync:x:100:101:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin systemd-network:x:101:103:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin systemd-resolve:x:102:104:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin messagebus:x:103:106::/nonexistent:/usr/sbin/nologin syslog:x:104:110::/home/syslog:/usr/sbin/nologin _apt:x:105:65534::/nonexistent:/usr/sbin/nologin tss:x:106:111:TPM software stack,,,:/var/lib/tpm:/bin/false uuidd:x:107:114::/run/uuidd:/usr/sbin/nologin tcpdump:x:108:115::/nonexistent:/usr/sbin/nologin avahi-autoipd:x:109:117:Avahi autoip daemon,,,:/var/lib/avahi-autoipd:/usr/sbin/nologin usbmux:x:110:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin rtkit:x:111:118:RealtimeKit,,,:/proc:/usr/sbin/nologin dnsmasq:x:112:65534:dnsmasq,,,:/var/lib/misc:/usr/sbin/nologin avahi:x:113:120:Avahi mDNS daemon,,,:/run/avahi-daemon:/usr/sbin/nologin cups-pk-helper:x:114:121:user for cups-pk-helper service,,,:/home/cups-pk-helper:/usr/sbin/nologin speech-dispatcher:x:115:29:Speech Dispatcher,,,:/run/speech-dispatcher:/bin/false kernoops:x:116:65534:Kernel Oops Tracking Daemon,,,:/:/usr/sbin/nologin saned:x:117:123::/var/lib/saned:/usr/sbin/nologin nm-openvpn:x:118:124:NetworkManager OpenVPN,,,:/var/lib/openvpn/chroot:/usr/sbin/nologin whoopsie:x:119:125::/nonexistent:/bin/false colord:x:120:126:colord colour management daemon,,,:/var/lib/colord:/usr/sbin/nologin sssd:x:121:127:SSSD system user,,,:/var/lib/sss:/usr/sbin/nologin geoclue:x:122:128::/var/lib/geoclue:/usr/sbin/nologin pulse:x:123:129:PulseAudio daemon,,,:/var/run/pulse:/usr/sbin/nologin hplip:x:124:7:HPLIP system user,,,:/run/hplip:/bin/false gnome-initial-setup:x:125:65534::/run/gnome-initial-setup/:/bin/false gdm:x:126:131:Gnome Display Manager:/var/lib/gdm3:/bin/false user:x:1000:1000:user,,,:/home/user:/bin/bash systemd-coredump:x:999:999:systemd Core Dumper:/:/usr/sbin/nologin shakir:x:1001:1001:shakir,,,:/home/shakir:/bin/bash

  3. Force the user to be logged out from the system. 

    $ sudo pkill -u shakir [sudo] password for user:

    Related: How to force user to logout in Linux

  4. Make sure the user is no longer logged in to the system. 

    $ who user     :0           2021-01-23 10:28 (:0)

  5. Backup home folder of user or any other files if required. 

    $ sudo cp -a /home/shakir /backup-shakir

  6. Delete user using userdel command. 

    $ sudo deluser shakir Removing user `shakir' ... Warning: group `shakir' has no more members. Done.

    Use –remove-home to also remove home directory. 

    $ sudo deluser --remove-home shakir

  7. Check if user information still exist just to confirm. 

    $ id shakir id: ‘shakir’: no such user $ grep shakir /etc/passwd $ grep shakir /etc/group $ ls -l /home total 8 drwxr-xr-x  5 1001 1001 4096 Jan  23 10:46 shakir drwxr-xr-x 15 user user 4096 Okt  25 09:28 user

    Home directory should not exist if you previously used –remove-home option.