Restrict Usernames
This plugin allows you to restrict the usernames that new users may use when registering for your site.
Consider an alternative
Restrict Usernames shows warning signs in 2026 — compare the alternatives below before installing. It runs on 200+ sites, is rated 3.6/5 and was last updated 8 years ago, and scores 32/100 on our health check.
- Small user base (200+ active installs)
- No update in 8 years
- Only tested up to WordPress 4.9 (latest is 7.1)
How does it stack up?
Side-by-side on installs, updates, ratings & supportDaily downloads
Download spikes usually follow a new release — each site that auto-updates counts as a download.
Rankings
Where Restrict Usernames stands todayWordPress.org search rankings
Live position in the plugin search, top 100| Keyword | Position |
|---|---|
| registration | >100 |
| restrictions | >100 |
| signup | >100 |
| username | >100 |
| users | >100 |
Version adoption
Share of active sites per release.
Rating breakdown
★★★★★★★★★★ 3.6 from 14 reviews
About Restrict Usernames
From the official readme · v3.7Description
This plugin allows you to restrict the usernames that new users may use when registering for your site.
If open registration is enabled for your site (via Settings -> General -> Membership (“Anyone can register”)), WordPress allows visitors to register for an account on your blog. By default, any username they choose is allowed so long as it isn’t an already existing account and it doesn’t include invalid (i.e. non-alphanumeric) characters.
Possible reasons for wanting to restrict certain usernames:
- Prevent usernames that contain foul, offensive, or otherwise undesired words
- Prevent squatting on usernames that you may want to use in the future (but don’t want to actually create the account for just yet) (essentially placing a hold on the username)
- Prevent official-sounding usernames from being used (i.e. help, support, pr, info, sales)
- Prevent official username syntax from being used (i.e. if all of your administrators use a prefix to identify themselves, you don’t want a visitor to use that prefix)
- Prevent spaces from being used in a username (which WordPress allows by default)
- Require that a username starts with, ends with, or contain one of a set of substrings (i.e. “support_”, “admin_”)
- Require a minimum number of characters for usernames
- Limit usernames to a maximum number of characters
When attempting to register with a restricted username, the visitor will be given an error notice that says:
ERROR: This username is invalid. Please enter a valid username.
NOTE: This plugin does not put any restrictions on usernames that the admin chooses for users when creating user accounts from within the WordPress admin. This only restricts the names that users choose themselves when registering for your site.
SPECIAL NOTE: Many membership plugins implement their own user registration handling that often bypasses checks (and hooks) performed by WordPress. As such, it is unlikely that the plugin is compatible with them without special plugin-specific amendments.
Compatible with Multisite and BuddyPress as well.
Links: Plugin Homepage | Plugin Directory Page | GitHub | Author Homepage
Hooks
The plugin exposes one filter for hooking. Typically, customizations utilizing this hook would be put into your active theme’s functions.php file, or used by another plugin.
c2c_restrict_usernames-validate (filter)
The ‘c2c_restrict_usernames-validate’ hook allows you to add your own customized checks for the username being registered. You can add additional restrictions or override the assessment performed by the plugin.
Arguments:
- $valid (boolean): The assessment by the plugin about the validity of the username based on settings. True means username can be used.
- $username (string): The username being registered.
- $settings (array): The plugin’s settings.
Example:
/**
* Add custom checks on usernames.
*
* Specifically, prevent use of usernames ending in numbers.
*
* @param bool $valid True if the username is valid, false if not.
* @param string $username The username.
* @param array $options Plugin options.
*/
function my_restrict_usernames_check( $valid, $username, $options ) {
// Only do additional checking if the plugin has already performed its
// checks and deemed the username valid.
if ( $valid ) {
// Don't allow usernames to end in numbers.
if ( preg_match( '/[0-9]+$/', $username ) ) {
$valid = false;
}
}
return $valid;
}
add_filter( 'c2c_restrict_usernames-validate', 'my_restrict_usernames_check', 10, 3 );
Installation
- Whether installing or updating, whether this plugin or any other, it is always advisable to back-up your data before starting
- Install via the built-in WordPress plugin installer. Or download and unzip
restrict-usernames.zipinside the plugins directory for your site (typicallywp-content/plugins/) - Activate the plugin through the ‘Plugins’ admin menu in WordPress. In Multisite, Network Activate the plugin.
- Go to the ‘Users’ -> ‘Name Restrictions’ admin settings page (which you can also get to via the ‘Settings’ link next to the plugin on the ‘Manage Plugins’ page) and specify username restrictions. On a Multisite install, go to ‘My Sites’ -> ‘Network Admin’ -> ‘Users’ -> ‘Name Restrictions’.
Changelog
Recommended minor update: bugfix for BuddyPress & Multisite; bugfix to make restricted usernames and conditions case-insensitive; updated plugin framework to v048; compatibility is now WP 4.7-4.9; updated copyright date (2018); added README.md; and more.
3.7 (2018-06-19)
Highlights:
- This release fixes a few bugs (notably one preventing username restrictions from working well for BuddyPress and Multisite) and makes numerous behind-the-scenes changes.
Details:
- Fix: Correct inverted conditional logic that prevented restrictions from being enforced for BuddyPress and Multisite
- Fix: Make restricted usernames and partial usernames case insensitive for comparisons
- Fix: Make username testing input field responsive
- Change: Update plugin framework to 048
- 048:
- When resetting options, delete the option rather than setting it with default values
- Prevent double “Settings reset” admin notice upon settings reset
- 047:
- Don’t save default setting values to database on install
- Change “Cheatin’, huh?” error messages to “Something went wrong.”, consistent with WP core
- Note compatibility through WP 4.9+
- Drop compatibility with version of WP older than 4.7
- 046:
- Fix
reset_options()to reference instance variable$options - Note compatibility through WP 4.7+
- Update copyright date (2017)
- 045:
- Ensure
reset_options()resets values saved in the database - 044:
- Add
reset_caches()to clear caches and memoized data. Use it inreset_options()andverify_config(). - Add
verify_options()with logic extracted fromverify_config()for initializing default option attributes. - Add
add_option()to add a new option to the plugin’s configuration. - Add filter ‘sanitized_option_names’ to allow modifying the list of whitelisted option names.
- Change: Refactor
get_option_names(). - 043:
- Disregard invalid lines supplied as part of hash option value.
- New: Add README.md
- Change: Store setting name in constant
- Change: Make untranslated strings translatable
- Change: Unit tests:
- Add tests for
bp_members_validate_user_signup() - Improve test initialization
- Improve tests for settings handling
- Default
WP_TESTS_DIRto/tmp/wordpress-tests-librather than erroring out if not defined via environment variable - Enable more error output for unit tests
- Add tests for
- Change: Minor code reformatting (spacing)
- Change: Add GitHub link to readme
- Change: Note compatibility through WP 4.9+
- Change: Drop compatibility with versions of WP older than 4.7
- Change: Rename readme.txt section from ‘Filters’ to ‘Hooks’
- Change: Modify formatting of hook name in readme to prevent being uppercased when shown in the Plugin Directory
- Change: Update copyright date (2018)
- Change: Update installation instruction to prefer built-in installer over .zip file
3.6 (2016-05-03)
Highlights:
- This release largely consists of minor behind-the-scenes changes.
Details:
- Change: Update plugin framework to 042:
- Change class name to c2c_RestrictUsernames_Plugin_042 to be plugin-specific.
- Set textdomain using a string instead of a variable.
- Don’t load textdomain from file.
- Change admin page header from ‘h2’ to ‘h1’ tag.
- Add
c2c_plugin_version(). - Formatting improvements to inline docs.
- Change: Add support for language packs:
- Set textdomain using a string instead of a variable.
- Remove .pot file and /lang subdirectory.
- Change: Amend description for max_length setting to indicate WP already enforces a max length of 60, which the plugin cannot increase.
- New: Hook ‘illegal_user_logins’ filter to add in usernames explicitly prohibited by the plugin.
- New: Add special note and FAQ item to readme indicating the likely lack of compatibility with membership plugins that have custom registration handling.
- Change: Declare class as final.
- Change: Explicitly declare methods in unit tests as public or protected.
- Change: Minor code reformatting.
- Change: Minor improvements to inline docs and test docs.
- Change: Prevent web invocation of unit test bootstrap.php.
- New: Add LICENSE file.
- New: Create empty index.php to prevent files from being listed if web server has enabled directory listings.
- Change: Note compatibility through WP 4.5+.
- Change: Remove support for versions of WordPress older than 4.1.
- Change: Update copyright date (2016).
3.5.1 (2015-04-16)
- Bugfix: compatibility fix for versions of WP older than 4.1;
$error->remove()was introduced in 4.1
3.5 (2015-02-20)
- Fix error message handling to override misleading default WP registration error message
- Update plugin framework to 039
- Add more unit tests
- Explicitly declare
activation()anduninstall()static - Reformat plugin header
- Change documentation links to wp.org to be https
- Minor documentation spacing changes throughout
- Note compatibility through WP 4.1+
- Update copyright date (2015)
- Add plugin icon
- Add Russian translation. props Kolya Korobochkin
- Regenerate .pot
3.4.1 (2014-01-15)
- Bugfix to prevent plugin from causing admin error/notice messages to appear twice
3.4 (2014-01-14)
- Fix to display settings page update messages and username test tool results
- Add setting to optionally enforce minimum length for usernames
- Add setting to optionally enforce maximum length for usernames
- Improve display of username test tool results:
- Display as list
- Color-code results as green or red
- Make ‘valid’ and ‘invalid’ translatable
- Add is_buddypress() to determine if BuddyPress’s user validation checks are being used
- Move descriptive text from top of settings page into Help panel under new ‘About’ tab
- Add unit tests
- Update plugin framework to 037
- Better singleton implementation:
- Add
get_instance()static method for returning/creating singleton instance - Make static variable ‘instance’ private
- Make constructor protected
- Make class final
- Additional related changes in plugin framework (protected constructor, erroring
__clone()and__wakeup())
- Add
- Add checks to prevent execution of code if file is directly accessed
- Use explicit path for require_once()
- Discontinue use of PHP4-style constructor
- Discontinue use of explicit pass-by-reference for objects
- Minor documentation improvements
- Minor code reformatting (spacing, bracing)
- Note compatibility through WP 3.8+
- Drop compatibility with version of WP older than 3.6
- Update copyright date (2014)
- Regenerate .pot
- Change donate link
- Update screenshot
- Add banner
For developers
Is this your plugin? Show off the numbers.
Add a live badge to your site, docs or GitHub README. It updates on its own — no account needed.
Best Restrict Usernames alternatives
All registration plugins →FAQ
Restrict Usernames: quick answers
Straight answers, pulled from live WordPress.org data.
Live data from WordPress.org · checked Sep 27, 2026
Is Restrict Usernames free?
Yes. Restrict Usernames is free to download and use from the official WordPress.org plugin directory.
Is Restrict Usernames safe to use in 2026?
Restrict Usernames shows warning signs in 2026 — compare the alternatives below before installing. It runs on 200+ sites, is rated 3.6/5 and was last updated 8 years ago, and scores 32/100 on our health check.
How many websites use Restrict Usernames?
Restrict Usernames is active on 200+ WordPress websites and has been downloaded 24,760 times since it launched in July 2009. It was downloaded 98 times in the last 30 days.
Does Restrict Usernames work with WordPress 7.1?
Restrict Usernames is officially tested up to WordPress 4.9.33, while the latest release is 7.1.2. It may still work, but try it on a staging site first.
When was Restrict Usernames last updated?
The latest version, 3.7, was released on June 21, 2018 (8 years ago).
Who makes Restrict Usernames?
Restrict Usernames is developed and maintained by Scott Reilly.
What are the best alternatives to Restrict Usernames?
The most popular alternatives to Restrict Usernames are WP-Members Membership Plugin (50K+ installs), User Profile Builder (40K+ installs) and WP Events Manager (30K+ installs).
Powered by PageForge
Want thousands of pages that rank like these? Build them in an afternoon.
This directory runs on the same engine as PageForge. Turn any spreadsheet, CSV or API into thousands of fast, SEO-ready WordPress pages — with schema, internal links and AI-written copy baked in.
- CSV, Google Sheets & API data sources
- AI content, schema & internal links per page
- Works with Elementor, Gutenberg, Yoast & Rank Math
- Free on WordPress.org — no credit card
