United Airlines has introduced an initiative to generate earnings while lowering rates for some travelers — but not everyone is happy with it.

According to the airline, the announcement of Basic Economy Fares “provides customers the option of paying the lowest fares to their destinations, while still receiving the same standard economy experience, including food, beverage, Wi-Fi and personal device entertainment, with a few key differences.”

However, the lower fares also mean that those travelers will see fewer benefits than they would otherwise, including being assigned seats on the day of departure, be assigned to boarding group five, and will be permitted only one carry-on item that has to fit under the seat.

“The new offering provides the added benefit for customers and employees of simplifying the boarding process, as fewer customers will bring overhead bags on board,” the airline explained.

United Airlines explained that the plan is expected to generate nearly $5 billion in earnings improvement by 2020.

“Customers have told us that they want more choice and Basic Economy delivers just that,” said Julia Haywood, executive vice president and chief commercial officer. “By offering low fares while also offering the experience of traveling on our outstanding network, with a variety of onboard amenities and great customer service, we are giving our customers an additional travel option from what United offers today.”

The new offering is not required for any travelers, and United Airlines assures their customers they still offer economy, Economy Plus, and domestic first class.

“As we approach the new year, our operations are running well, our employees are more energized than ever, and we are ready to unlock United’s full potential,” said Oscar Munoz, chief executive officer. “Today, we are talking about what’s next for United. We now have the strategy and organization in place to be the best airline in the world – for employees, customers and investors.”

Complete details on Basic Economy can be found here.