# Validate Phone Numbers in Contact Form 7

> Checks Contact Form 7 phone fields for a realistic number of digits and only the characters phone numbers use, instead of accepting any text.

- Type: PHP
- Runs: Run everywhere
- Category: [Forms](https://wpide.com/library/category/forms/)
- Tags: contact-form-7, validation, phone
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/cf7-phone-validation/

## Code

```php
$wpide_cf7_phone_min_digits = 7;
$wpide_cf7_phone_max_digits = 15;

$wpide_cf7_phone_check = function ( $result, $tag ) use ( $wpide_cf7_phone_min_digits, $wpide_cf7_phone_max_digits ) {
    $phone = isset( $_POST[ $tag->name ] ) ? trim( (string) wp_unslash( $_POST[ $tag->name ] ) ) : '';

    if ( '' === $phone ) {
        return $result;
    }

    $digits = strlen( preg_replace( '/\D/', '', $phone ) );

    if ( ! preg_match( '/^\+?[0-9\s().\-]+$/', $phone ) || $digits < $wpide_cf7_phone_min_digits || $digits > $wpide_cf7_phone_max_digits ) {
        $result->invalidate( $tag, 'Please enter a valid phone number.' );
    }

    return $result;
};

add_filter( 'wpcf7_validate_tel', $wpide_cf7_phone_check, 20, 2 );
add_filter( 'wpcf7_validate_tel*', $wpide_cf7_phone_check, 20, 2 );
```

## Notes

Adjust the minimum and maximum digit counts for your country; spaces, dashes, dots, brackets and a leading + are always allowed.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Validate Phone Numbers in Contact Form 7" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/