Since October 2025, every foreign visitor arriving in Taiwan by air or sea — Irish passport holders included, visa-free entry notwithstanding — completes the Taiwan Arrival Card (TWAC) before the border. The update worth noting: the filing window has grown from three days to seven days before arrival, per the official portal, so the form can be done before an itinerary that routes through the Gulf or Southeast Asia even begins.
The card gathers passport data, purpose of travel, flight or vessel details and your accommodation, behind an e-mail verification; travellers on a shared itinerary can be bundled into one submission. Corrections stay possible until the document check at immigration — keep the electronic confirmation, whose document number (with date of birth, passport number and nationality) reopens the form.