[header] How to pay internet sales tax [title] Determine the states in which you must collect sales tax. [step] Generally, you must collect sales tax if your business has a physical location within that state. [substeps] Whether you are required to collect sales tax also depends on how large your online business is. 
Some states have so-called " amazon laws " that require online merchants with sales over a certain dollar amount to collect sales tax even if they don't have a physical presence in the state. Having a physical presence in a state doesn't just mean a store.