Travellers from Ireland seeking to obtain the ESTA permit required for visa-free travel to the US are experiencing difficulties due to payment issues on the Electronic System for Travel Authorisation website. The website is preventing users from completing payment, and instead displays an error message. The $21 fee must be paid to complete the application, and without payment the application will be deemed incomplete and cannot be processed by U.S. Customs and Border Protection. This prevents travellers from entering the country under the Visa Waiver Program for business or tourism purposes for up to 90 days. The issue has prompted Twitter users to seek clarity from U.S. Customs and Border Protection, and similar problems have been reported by users across Europe, Asia, and Australia. The federal agency has yet to provide an official update, but it has confirmed that the issue is being resolved.