The IndiGo offering comes two months afte SpiceJet introducing a similar service.
IndiGo has come up with an offer that allows customers to change their booking as many times as they want, by paying a one-time flat fee while purchasing the ticket.
"You can opt for this service by selecting 6E Plus option available at the bottom of the flight selection page," IndiGo said.
IndiGo will charge a fee of Rs 1,000 (inclusive of tax) for those who choose the service at the time of booking. The move is aimed at travellers whose travel plans may be subject to change. "For just Rs.1000, enjoy unlimited flexibility and fly hassle-free every time," IndiGo said.
The IndiGo scheme comes after rival budget airline SpiceJet in July introduced a similar offering that allows customers to cancel or change tickets "anytime", by paying a flat fee during booking.
The flat fee charged by SpiceJet for the add-on service is Rs 899 for domestic travel and Rs 1099 on international tickets.