Organised by Community Foundation for Calderdale, the online collection is aimed at helping the small businesses who were housed in the building on Hangingroyd Lane, including La Perla restaurant.
The page says: "This appeal fund is to support the businesses who've lost stock and equipment in the fire.
"A small business is more than just an income. It's someone's passion and dreams. Let's support them to rebuild.
"We rally in the Upper Calder Valley, so please give generously."
Dozens of firefighters were called to the blaze at 2.12am today, at Burlees House offices and La Perla.
People were initially reported in the building but the fire service has said everyone has been accounted for.
Several roads were shut and firefighters were still at the scene this afternoon.
The owner of La Perla, who has run the restaurant for 12 years, said: "The whole building has burned down.
"I am gutted. It's heartbreaking."
To donate, visit https://localgiving.org/appeal/BurleesHouseFire/