Yes, you must check in for every KLM flight to confirm your attendance and receive your boarding pass. In 2026, KLM offers several convenient ways to do this. The most popular method is online check-in, which typically opens 30 hours before departure (or 24 hours for flights to/from the United States). You can check in via the KLM website or mobile app using your 6-character booking code or 13-digit ticket number. If you prefer to do it at the airport, you can use the self-service kiosks or visit a check-in desk, though arriving early is advised as these close 40–60 minutes before departure depending on the destination. Checking in early allows you to select your seat, purchase extra baggage at a discount, and ensure your travel documents (like the new EES biometric registration for non-EU passengers entering the Schengen area) are in order.