Where do the tax rates come from, and how current are they?

Every country has a tax profile with standard, reduced and zero rates, each with a validity period and the official source, which is linked below the result. The profiles are reference data with an as-of date; a review process by Peak hasn't been built yet. For older receipts you choose a reference date, and Peak calculates with the rate that applied on that day. You can always enter your own rate.