How do you know what sales tax to charge on the web?

[sathenzar]

If you want to sell web services on the web or products in general, do you charge sales tax for your area or the customers? Or is there a time you don't charge sales tax on the web for services at all?

[+Biscuits Brown MVC]

Rule of thumb is if you have a physical presence in the state you must collect sales tax appropriate for that state.   Here is a guide.

 

Here is another that breaks it down by state at nolo