 If a new income tax bill was passed after the FairTax passage, a combined system could develop.However, there is nothing preventing the addition of a national sales tax, or VAT tax, on top of today's income tax system.The Americans For Fair Taxation plan is to first pass the FairTax and then to focus grassroots efforts on HJR 16, sponsored by Congressman Steve King (R-IA), that calls for the repeal of the Sixteenth Amendment.