Fourteen businesses within the Primark safety cordon will be unable to trade for at least 4 months while engineers assess the building's integrity.
Belfast's Lord Mayor Deirdre Hargey said there will also be no access for pedestrians down Royal Avenue.
Sara Moore was live in Belfast city centre:
Belfast City Council met with city centre traders affected in the wake of the Primark fire on Wednesday afternoon.
The council will hold group and one-to-one meetings with affected businesses in order to understand all of their individual issues.
The council and other government departments are working together to find alternative premises for the businesses.
Advice will also be on hand regarding rates and employability.
Over the coming days, engineers will assess the damage of the building before drawing up a plan.
Once such plan of action could include building a bracing solution to secure the Bank Buildings.
The engineers will be able to determine if the façade can be saved.
On Thursday, Belfast City Council will put signage in place to help navigate people around the city centre while the cordon remains in place.
The Council and its city partners is also planning a campaign aimed at sustaining visitors to the city.
Councillor Hargey added: “We will be doing everything we can to restore the city to the very vibrant place that it is, and, it is vital that as a city, we continue to rally round to support those affected by this event both directly and indirectly."