The Beijing Development and Reform Commission has reportedly fined China United Airlines for charging passengers to choose their seats from March 29 to Dec 23, 2015.

The airline was fined 443,210 yuan ($66,811) as that was the amount the airline made from 26,853 passengers who paid to select their seats from between March 29 and Dec 23, 2015.

Some experts said fining China United Airlines shows that arbitrary charges are forbidden in the aviation industry.

Low-cost airline Spring Airlines began to charge a seat selection fee as early as 2005. But many passengers still regard it as unreasonable and even greedy for an airline to charge passengers for choosing their preferred seat.

But internationally, many airlines charge for seat selection as a single service item, especially low-cost airlines. And some people argue it is reasonable to charge for selecting seats because it is in accordance with the market rules that people should pay to tailor a service to their preferences.