They can match up rate to location, but most jurisdictions have their own laws on what items are taxable. There are also jurisdiction-dependent tax holidays. F

They can match up rate to location, but most jurisdictions have their own laws on what items are taxable. There are also jurisdiction-dependent tax holidays. For example, Texas has a weekend in August where certain kinds of items (that are "back-to-school" appropriate) are tax free. So you have to know not only the rate, but also the rules for categorization, and those vary by jurisdiction and time of year, sometimes differently from year to year.