Add Extra Confirm Password Field in Registration and Checkout Page

By default in WooCommerce plugin Confirm Password field is included in theme, so we need to customize the functions.php to show these password fields, and also in the confirm password at the checkout page.

Depending on the website, Confirm password field is important cause many users miss type the password in the registration form, to avoid this, Confirm Password field is the key.

We will add a bit of code in the functions.php, located in your Theme folder

Put this code in your functions.php on your active theme:

// ----- validate password match on the registration page
function registration_errors_validation($reg_errors, $sanitized_user_login, $user_email) {
	global $woocommerce;
	extract( $_POST );
	if ( strcmp( $password, $password2 ) !== 0 ) {
		return new WP_Error( 'registration-error', __( 'Passwords do not match.', 'woocommerce' ) );
	}
	return $reg_errors;
}
add_filter('woocommerce_registration_errors', 'registration_errors_validation', 10,3);

// ----- add a confirm password fields match on the registration page
function wc_register_form_password_repeat() {
	?>
	<p class="form-row form-row-wide">
		<label for="reg_password2"><?php _e( 'Password Repeat', 'woocommerce' ); ?> <span class="required">*</span></label>
		<input type="password" class="input-text" name="password2" id="reg_password2" value="<?php if ( ! empty( $_POST['password2'] ) ) echo esc_attr( $_POST['password2'] ); ?>" />
	</p>
	<?php
}
add_action( 'woocommerce_register_form', 'wc_register_form_password_repeat' );

// ----- Validate confirm password field match to the checkout page
function lit_woocommerce_confirm_password_validation( $posted ) {
    $checkout = WC()->checkout;
    if ( ! is_user_logged_in() && ( $checkout->must_create_account || ! empty( $posted['createaccount'] ) ) ) {
        if ( strcmp( $posted['account_password'], $posted['account_confirm_password'] ) !== 0 ) {
            wc_add_notice( __( 'Passwords do not match.', 'woocommerce' ), 'error' ); 
        }
    }
}
add_action( 'woocommerce_after_checkout_validation', 'lit_woocommerce_confirm_password_validation', 10, 2 );

// ----- Add a confirm password field to the checkout page
function lit_woocommerce_confirm_password_checkout( $checkout ) {
    if ( get_option( 'woocommerce_registration_generate_password' ) == 'no' ) {

        $fields = $checkout->get_checkout_fields();

        $fields['account']['account_confirm_password'] = array(
            'type'              => 'password',
            'label'             => __( 'Confirm password', 'woocommerce' ),
            'required'          => true,
            'placeholder'       => _x( 'Confirm Password', 'placeholder', 'woocommerce' )
        );

        $checkout->__set( 'checkout_fields', $fields );
    }
}
add_action( 'woocommerce_checkout_init', 'lit_woocommerce_confirm_password_checkout', 10, 1 );

With this code we added field and label for password confirm, both in my account page and checkout page, then the password validate if the password is mismatch or not, the password confirm is not saved in the Database, it will be same process by default in WooCommerce plugin, this code works and tested.