[semimojo]

I agree that a single-rate flat tax is marginally simpler for the taxpayer - they don’t have to look at a table to determine the tax percentage - but I don’t see how it simplifies the administration of the system.

Most of the complexity in the system is in determining what is income, not in figuring out what rate to pay on that income.

[Taxman]

You are correct!

The so-called “Flat Tax” is still an income tax, and I can make the case that a flat income tax will cause the IRS to become even more intrusive and antagonistic towards the citizenry (that would be US!).

[Svartalfiar]

Most of the complexity in the system is in determining what is income, not in figuring out what rate to pay on that income.

True, but both flat and progressive tax systems will have that same problem. There is nothing in that that makes one more complicated or less so than the other.

There is withholding on all employees both full and part-time. Then there are all the rules on who is an official “employee”. Add to this, determining just exactly what is “income” and there will be thousands of pages of rules on that.

Then add to this the mischief that politicians can do to all those regulations.

Withholding should be entirely optional. Also, that has no effect on income or tax rate, it's just a pay-as-you-earn taxing system. And there shouldn't be nearly as many regulations as there are now. Any kind of subsidy, deduction, credit, etc. is all ridiculous and has no place in our system.

Besides, once you actually manage to go to a state-level tax system, you won't have nearly as many issues with the FedGov trying to do any of that. Some states may have that issue, but many won't.