How to change an username on Linux Ubuntu

To change a username in Ubuntu cleanly and safely, follow these steps from a different admin account (not the one you’re renaming) — or from a root shell.

⚠️ Important:

• You can’t rename the user while logged in as that user.
• Make a backup of any important data before proceeding.

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🧑‍💻 Step-by-Step: Renaming a User in Ubuntu

1. Log in as a different admin user (or root)

If you only have one account, you can:

• Boot into recovery mode, or
• Use sudo -i to get a root shell from another user with sudo rights.

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2. Check the current username

whoami

Or list all users:

cut -d: -f1 /etc/passwd

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3. Change the username

Replace oldusername with the current username and newusername with the desired name:

sudo usermod -l newusername oldusername

• -l changes the login name.
• This does not rename the home directory automatically.

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4. Rename the home directory (optional but recommended)

sudo usermod -d /home/newusername -m newusername

• -d specifies the new home directory.
• -m moves the old home contents to the new folder.

If you prefer to rename manually:

sudo mv /home/oldusername /home/newusername

sudo usermod -d /home/newusername newusername

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5. Update group name (optional, but tidy)

If you want the primary group to match the new username:

sudo groupmod -n newusername oldusername

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6. Update any references

You may need to:

• Update sudoers if you added the user explicitly there.
• Check scripts, cron jobs, or services that referenced the old name.
• Log out and back in as the new user.

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7. Reboot (recommended)

sudo reboot

After reboot, log in with:

newusername

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✅ Example
Renaming john to andrew:

sudo usermod -l andrew john

sudo usermod -d /home/andrew -m andrew

sudo groupmod -n andrew john

sudo reboot

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