Iberia allows passengers to check in online or via its mobile app starting 24 hours before departure, and online check-in closes one hour before the scheduled departure time for most destinations; however, for flights departing from or arriving to countries such as the United States, United Kingdom, Cuba, Mexico, Guatemala, Puerto Rico, El Salvador, and China, online check-in opens exactly 24 hours beforehand regardless of fare([turn0search5], [turn0search9], [turn0search10]). In addition to online options, airport check-in counters and self-service kiosks generally open three hours before departure for international flights and two hours before departure for short- and medium-haul routes, but travelers are encouraged to arrive three hours early, especially at busy Spanish airports([turn0search3], [turn0search7], [turn0search0]). The cut-off time for check-in and baggage drop at the airport is typically 45 minutes before departure for short- and medium-haul flights, and up to 60 minutes or more for long-haul routes, including destinations in Africa or Tel Aviv, and even up to 75 minutes or 120 minutes for flights to Buenos Aires, Quito, Peru, or Caracas depending on the airport([turn0search0], [turn0search7], [turn0search10], [turn0search2]). Boarding gates close 20 minutes before departure, so passengers must reach the gate well in advance ([turn0search2], [turn0search7]). Iberia further advises that travelers flying to the U.S. from Madrid arrive at the check-in desk at least four hours before departure, and proceed to the boarding gate 90 minutes prior due to enhanced security checks([turn0search2], [turn0search9]). While online check-in permits seat selection and mobile or printable boarding passes, passengers who plan to check baggage must still drop off their bags at the airport before the relevant cut-off, as online check-in does not replace baggage check-in ([turn0search4], [turn0search3]). Some passengers also report technical issues when trying to submit passport or travel documentation online; in such cases Iberia recommends arriving early to complete check-in at the counter instead([turn0reddit14], [turn0reddit19]). Ultimately, although Iberia provides online and kiosk check-in options up to one hour before departure, practical airport check-in windows and requirements mean you should plan to arrive 2 to 4 hours early depending on flight type and route, ensuring enough time for document verification, baggage drop, security, and reaching your boarding gate.

Let me know if you’d like this adapted into a checklist or airport signage format!