The Union Ministry of Civil Aviation announced on Monday that it is reviewing airlines’ policies of charging customers for web check-ins of all flight seats. “We are reviewing these fees to see whether they fall within the unbundled pricing framework,” the ministry said on Twitter.

The announcement came after budget airlines IndiGo and SpiceJet said on Sunday that they will charge money for online check-in services but will continue to allocate seats for free for airports check-ins. The new policy has been in place since November 14, IndiGo said. While low-cost airline GoAir still offers some seats for free, other carriers like Jet Airways and Vistara said they will not charge for seats, according to Business Standard.

IndiGo’s charges for seat selection start from Rs 100, while those for SpiceJet start from Rs 99. Till now, passengers had to only pay while selecting particular seats, such as ones along the aisle or those with extra leg space, online.

“Based on our customer preference we have made some changes in pricing for advance selection of seats,” IndiGo said in a statement. “This is a usual practice followed by airlines globally and across India.” Globally, however, most airlines urge customers to check-in online.

The announcement has drawn angry reactions on social media. However, aviation experts said that airlines are allowed to charge as they wish as the Directorate General of Civil Aviation permits the unbundling of services. “Airlines are not in violation of law,” Lalita Bhasin, a partner at a law firm, told Business Standard. “According to rules, they can charge such services.”