One of the most important considerations when deciding to buy an air ticket, is when it has to be paid. Not all airfares have to be purchased immediately. The cheapest airfares usually require payment straight away, as do airfares that apply over peak periods. However, more expensive airfares usually have greater flexibility in regards to payment deadlines.
Open-dated tickets are air tickets that can be purchased without a fixed date on one or all of the sectors. They are generally more expensive than standard airfares.
Instant Purchase Airfares
Cheap airfares often require payment straight away. These are called instant purchase airfares because the airfares quoted are only valid if they are purchased instantly or at the time of reservation.