That is the point. Unless you total the tax, all year long, from every receipt, then adjust for you monthly prebate, you won't know EITHER the amount of tax you paid NOR your real (effective) tax rate.
You did not address that point.
I said nothing about knowing you're "rate" ... but that's all you focused on. What you say is actually insufficient to determine your true tax burden.
For all it's warts, at least I know how much I pay in Federal taxes: 80% to 95% of my total burden is printed, in plain sight on my paystubs and W2. 85% to 95% of it is finalized on my 1040. The other 5% to 15% is truly hidden ... but it's easy to figure out, and it's very small part of my overall burden.
Nonsense. And I'm sick of this canard.
How much did you spend over the course of a year? Simple -- take your income from all sources and subtract your net savings, multiply that by the NRST (tax-inclusive) rate, and there's your total taxes paid.
For effective taxation, subtract twelve times the monthly FCA "prebate" from the total taxes you paid out.
The only way this gets anywhere even close to complicated is if a significant portion of your purchases are for used/previously-taxed goods, which would not be subject to the NRST -- the total amount spent here would need to be subtracted from the "income minus savings" total before calculating taxes. Other than that exception, however, this whole idea of having to add up each receipt is laughably pointless.