Businesses must collect sales tax unless protected by Public Law 86-272.

Public Law 86-272 is a United States law that provides a specific exemption for certain businesses from the obligation to collect sales tax. This law protects businesses whose only activity in a state is the solicitation of orders for sales of tangible personal property, so long as those orders are sent outside the state for approval and, if approved, are filled by shipment or delivery from a point outside the state.

Here are the steps a business should take to determine if they must collect sales tax:

1. Determine the nature of the business: If the business involves the sale of tangible personal property, it may be protected by Public Law 86-272.

2. Evaluate the business activities: If the only business activity in a state is the solicitation of orders, which are sent outside the state for approval and fulfillment, the business may be exempt from collecting sales tax.

3. Check the location of approval and fulfillment: If the orders are approved and fulfilled outside the state, the business may not need to collect sales tax.

4. Consult with a tax professional: Tax laws can be complex and vary from state to state. It's always a good idea to consult with a tax professional to ensure the business is in compliance with all applicable laws.

Remember, this law only applies to the United States. If the business operates in other countries, it will need to comply with the tax laws of those countries.