United Airlines says it will accept tickets it mistakenly sold last week for next to nothing.
A pricing error on the company's website on Thursday meant some travellers paid only the security fee of $US5 or $US10 on domestic flights.
"We've reviewed the error that occurred yesterday and based on these specific circumstances, we will honour the tickets," the company posted on Twitter.
Some of the tickets - such as from east coast cities to Hawaii - would normally have cost close to $US1000.
The company did not say how many tickets had been sold at the wrong prices.