No. of Recommendations: 7
How the heck do you administer that??? Seriously!
Require a national tax ID number be associated with every purchase. If you choose not to provide it, you get charged the maximum tax rate at point of sale.
Here in Portugal businesses are strongly encouraged, but not required to collect a NIF number on purchases. An upside is that allowed spending deductions automatically show up on the tax portal without needing to enter receipts by hand. Unlike SSNs, NIFs are not treated as a secret holy number through which your entire identity will be lost if revealed - they are handed out everywhere without concern.