If companies want to save money on business travel, they’re not doing it by flying employees in basic economy.

A new CNBC report shows no-frills fares are not filled by corporate travelers. United Airlines, Delta Air Lines and American Airlines all rolled out the basic economy fares, which give travelers little more than an airplane seat and require purchases for all add-ons, like a seat assignment and carry-on bags.

More than three out of four of American Express Global Business Travel’s clients blocked such fares and other corporate travel planners received similar directives. No members of Expedia’s Egencia business-travel booking service permit booking in basic economy, either.

“As the airlines have introduced them, we have blocked them,” said Amy Nutter, spokeswoman, the investment firm Robert W. Baird. “All along, we have viewed them as more suitable for leisure travellers and did not feel they met the needs of our business travelers.”

Delta president Glen Hauenstein said most of the airline’s corporate clients blocked basic economy fares while the carrier is trying to entice business travelers to upgrade to its Comfort+ service, offering more legroom.