Airbnb is buying HotelTonight, the hotel-booking application that lets travelers arrange last-minute accommodations.

The financial terms weren’t disclosed, but sources told Axios the homeshare giant paid close to Hotel Tonight’s last private valuation of about $463m. This would make it Airbnb’s largest acquisition ever.

HotelTonight partners with hotels to offer un-sold rooms, catering to business travelers or those looking to make last-minute arrangements.