TORONTO — Business travellers are increasingly booking stays through Airbnb and other home-sharing sites.

Airbnb said Monday that nearly 700,000 companies have signed up and booked rooms through its business travel portal, almost triple the number since last year.

Airbnb’s corporate travel business has been growing exponentially. In 2015 Airbnb for Business (now known as Airbnb for Work) had 250 companies signed up for corporate travel stays. Two years later that number had climbed to 250,000 companies.

Airbnb says 15% of its travel nights booked are for business travellers. That compares with 20 per cent for Booking.com, which includes homes and hotels on its site.

SAP Concur, which handles travel and expenses for more than 43,000 businesses, says home-sharing is especially appealing when hotel rooms are in short supply. This month, it’s adding Airbnb accommodations to its search options.

But home-sharing companies have a long way to go to catch up to hotels. Marriott International says business travel accounts for 70 to 80% of nights booked at its hotels.