Flight code and number There's generally a simple formula for this one: two uppercase letters, followed by a four-digit number. The letters are the airline code, or the numbers universally recognized to represent the name of the airline in shorthand. Some are obvious—AA is American Airlines, for example.

Reading a plane ticket involves understanding the Fare Basis Code, a string of letters and numbers that dictates the rules of your ticket. The first letter is the most important as it indicates the "Booking Class": F or A (First Class), J, C, D, I, or Z (Business), W or P (Premium Economy), and Y (Full-fare Economy). Letters like K, L, Q, V, or N signify various levels of discounted or "Basic" Economy. Following the first letter, the code might include: H or L (High or Low season), 7, 14, or 21 (the number of days in advance you had to book), and W or X (Weekend vs. Weekday travel). You might also see NR (Non-Refundable) or OW/RT (One-Way/Round-Trip). For example, a code like YHE7NR would mean: Full-fare Economy (Y), High Season (H), Midweek/Evening (E), booked 7 days out (7), and Non-Refundable (NR). Understanding these codes is vital in 2026, as the specific letter determines how many frequent flyer miles you earn, your priority for upgrades, and whether you are eligible for a refund or a free seat change if your plans shift at the last minute.