VANCOUVER - The city of Vancouver is moving to legalize short-term rental accommodation like Airbnb but operators will only be able to advertise their principal residence.

Vancouver Mayor Gregor Robertson says the move is to protect and free up rental housing in response to a critically low vacancy rate.

There are roughly 6,600 short term rentals posted online, and more than 80 per cent will remain legal under the program.

Operators will be required to apply for a business licence by Sept. 1 and include the number in their listing, which Airbnb has agreed to make as a requirement on its platform.

The cost of the license is $49 annually, and operators must have permission from their landlord or condo board and adhere to fire and safety standards.

There are about 1,000 units currently listed that are not an operator's primary home and Robertson says they should go back on the rental market, or be subject to a $1,000 a day fine.