The gform_signature_url_require_login filter can be used to require the user be logged in before the signature URL will allow access to the file.


The following would apply to all forms.

add_filter( 'gform_signature_url_require_login', 'your_function_name', 10, 3 );


  • $require_login bool

    Does the user need to be logged in to access the signature? Default false.

  • $form_id int

    The ID of the form used to create the requested signature.

  • $field_id int

    The ID of the field used to create the requested signature.


1. Require login for all forms

add_filter( 'gform_signature_url_require_login', '__return_true' );

2. Require login for specific form and field

add_filter( 'gform_signature_url_require_login', 'require_login_for_signatures', 10, 3 );
function require_login_for_signatures( $require_login, $form_id, $field_id ){

  	// Update values below to match your form and field id's
	if  ( $form_id == '97' && $field_id == '2' ) {

		$require_login = true;

	return $require_login;


This code should be placed in the functions.php file of your active theme or a custom functions plugin.


This filter was added in version 4.0.

Source Code

This filter is located in GF_Signature_Image::maybe_require_login() in includes/class-gf-signature-image.php.