Whether the confirmation number (also known as a PNR or Booking Reference) is the same for both flights depends on how the tickets were purchased. If you booked a single itinerary with one airline (e.g., a flight from New York to London with a connection in Dublin), you will almost always have one single confirmation number for the entire trip. However, if you booked a "multi-city" trip involving different airlines that do not have a codeshare agreement, you might receive a separate confirmation number for each carrier. This is common when using "hacker fares" or third-party booking sites like Kiwi or Expedia that combine separate tickets. For international travel, it is vital to check your "Manage Booking" page; even if you have one "Master" reference from the booking site, you may need the specific Airline Record Locator for each individual airline to check in online or select your seats.