said it will begin collecting sales tax in Florida starting next month, affecting as many as 20 million people in the nation’s fourth-largest state by population.

Florida is the 21st state to charge sales tax for purchases made on Amazon.

By Greg Bensinger

The 6% sales tax comes as a result of Amazon’s plans to build two new warehouses in the Sunshine State, in Ruskin and Lakeland, which ring Tampa and are near to Orlando. Online retailers are generally not subject to sales tax unless they have a physical presence in a state, such as offices, warehouses or affiliates located there.

The Florida Retail Federation estimates the tax will bring in roughly $80 million in new revenue annually to state coffers.

With the addition of Florida, nearly 190 million Americans–roughly 60% of the populace–would be subject to sales tax for their purchases from the Seattle-based retailer.

Florida is the 21st state to charge sales tax for purchases made on Amazon. Later this year about 6 million Marylanders will also pay sales tax on Amazon purchases.

Amazon battled for years to remain free of sales tax, hoping to retain a competitive advantage over brick-and-mortar retailers. In some states the company cut off business relationships with smaller firms located there because of concerns it could trigger sales tax.

However, Amazon’s position on sales tax has softened and it is now on a warehouse building spree that has triggered the levies in a number of states. Amazon also has lobbied in favor of a national sales tax for all online retailers, known as the Marketplace Fairness Act.

Under a version passed last year by the U.S. Senate, retailers with at least $1 million in annual sales outside of their home states would need to collect sales tax from their customers, wherever they reside.

An Amazon spokesman declined to say when sales tax may take effect in Maryland, where the company is building a new warehouse in Baltimore. A spokesman for the state’s comptroller’s office didn’t immediately return a call seeking comment.