You can readily identify an e-Passport, because it has a unique international symbol on the cover. Electronic System for Travel Authorization (ESTA) ESTA is an automated system that determines the eligibility of visitors to travel to the United States under the Visa Waiver Program (VWP). Authorization via ESTA does not determine whether a traveler is admissible to the United States.
Two to three weeks before the flight date, the price quotes start increasing. This is the time when business travelers start booking. While price drops are still possible, a chance of a price increase is much higher if you wait to book within this time period.
One, Tuesday at 3 p.m. is when most airlines release their fares for the week. So there's the most competition for your dollar. Two,the data shows that 50-100 days before your domestic flight takes off is the longest stretch of time before fares start going up as seats start selling. Each tip works on its own, but combine them and you can save on average over $100.