Free US sales-tax lookup (per zip etc.)?

Question

I am creating a pricing program. I need to calculate the amounts according to the current tax list in the US (in various places).

I want to have a button 'Update taxes' in the administrative settings of the application, so when the user clicks it, it should download from somewhere the active tax amounts.

So I actually want to have a function decimal GetTax(string zip).

Does anyone knows about a free downloadable xml, or RSS accessible or even a website that I can crawle in and get this info from?

Answer 1

There are a number of third-party solutions out there. Here is one:

http://www.avalara.com/Products/Integrations/Ecommerce?gclid=CI2CyKfuu6ECFZIU5wodtUWW_w

Answer 2

Try http://www.telcotax.com/?