Taxpayer Fairness Fund Act of 2020 This bill establishes the Taxpayer Fairness Fund to enhance Internal Revenue Service (IRS) enforcement activities. The fund provides amounts for the hiring, training, and employment of IRS personnel to determine and collect owed taxes from individuals with annual incomes of $500,000 or more and corporations with assets valued at $5 million or more. The fund is financed by voluntary designations of certain taxpayers on their tax returns of $5.00 from overpayment of tax.