IndiGo claimed on Monday it had not changed its web check-in policy, saying some seats “may be available” for free online check-in, “depending on the market dynamics for the flight”.

A few hours later, a customer support executive on IndiGo’s website replied to an enquirer: “All seats are now chargeable.”

The executive’s statement was in line with what many passengers had understood on Sunday: web check-in comes with a fee.

On Monday, something else took place. The civil aviation ministry said it would carry out a review, after noting that “airlines are now charging for web check-in for all seats”. “We are reviewing these fees to see whether they fall within the unbundled pricing framework,” the ministry said in a tweet.

It is not clear whether the official statement by IndiGo was in response to the government’s tweet and whether the information is yet to trickle down to the customer support system.

The airline said in Monday’s statement: “IndiGo customers will not compulsorily have to pay for the seats…. While the preferred seat pricing starts as low as Rs 100, there would be some seats that may be available for free, depending on the market dynamics for the flight. Thus, there are some seats that are available for free at a certain time period before departure (e.g. one day before departure) or on certain aircraft type (e.g. ATR-operated flights).”

ATR flights operate to small, regional destinations.

What IndiGo seems to be suggesting by “dynamics” is that if many seats are vacant on some flights, they will be offered for free web check-in.

Data show that IndiGo achieved a passenger load factor (PLF) of 83.1 per cent in October. What this means is that only 17 per cent of available seats on all IndiGo flights remain vacant. SpiceJet’s PLF was higher at 90.8 per cent.

Most flights between metros run to capacity and, therefore, passengers will most likely have to pay when they make an advance selection of seats.

The web check-in fee will vary from row to row, depending on where the seat is located in the plane. The fees range from Rs 100 to Rs 800 a seat.

Seats that are assigned at the airline counters at airports will remain free.

Many passengers are angry because they do not appear to have been told in advance of any change. Once the customer support system started informing passengers that “all seats are chargeable” since November 15, there was no visible effort to clear the air either.

The Air Transport Circular of 2016, which lays down the guidelines for “unbundling” of services and fees that airlines could levy, requires an airline to announce the change at least 30 days in advance.

The unbundling pricing framework gives airlines the right to charge a fee for preferential seating, excess baggage and lounge access facility.

The circular had said that unbundling “has the potential to make the basic fare more affordable and provides consumer an option of paying for the services which he/she wishes to avail”.

It listed the unbundled services as preferential seating, meal/snack/drink charges (except drinking water), check-in baggage charges above 15kg, sports equipment, musical instrument, and special declaration of valuable baggage.

Scheduled airlines are required to display the unbundled services and charges on their respective websites in a transparent and conspicuous manner. They must also display on their respective websites in a transparent and conspicuous manner that the booking/reservation can be made without opting/availing the unbundled services.

On Monday, SpiceJet said that “pre-allocation of seats through web check-in is on chargeable basis”.

“If a passenger does not wish to pay for a seat, he/ she may request for a preferable seat while check-in at the airport. Our team shall provide the seat without charges, if available,” the airline said in reply to a customer’s query.

This was in response to a tweet saying that web check-in at SpiceJet is chargeable. The airline does not allow check-in unless a seat is booked. There was no statement from SpiceJet about its web check-in policy.

IndiGo posted a loss of Rs 652 crore in the second quarter (July-September) while SpiceJet reported a loss of Rs 389.37 crore.

The Indian Railways struck while the iron is hot. “Why pay a premium for a web-check-in on flights... when you can just take a train. No need to pay extra charges for web check-in. No long queues for checking in your luggage. Avoid unreasonable tariff and reduce your carbon footprint by travelling on the good old Indian Railways at affordable rates,” the railway ministry tweeted.

The Telegraph