In general, a 20% penalty applies to tax underpayments attributable to a substantial valuation misstatement.

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This can retroactively remedy tax underpayments from earlier in the year and avoid a potential underpayment penalty.

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Ninth Circuit, Keller agreed the tax underpayments were attributable to invalid deductions, but not to any asset overvaluation.

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It includes overpayments and underpayments, unnecessary services, coding errors and other problems.

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It would be 10 more years before this ticking time bomb went off, bringing with it the full force of a decade's worth of alleged underpayments and penalties.

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In return for escaping criminal charges, taxpayers accepted into the current version of the OVDP must file eight years of amended tax returns, pay all back taxes, interest and penalties due (including a 20% accuracy penalty on offshore-related underpayments) and pay an FBAR penalty equal, in most cases, to 27.5% of the maximum held in the undisclosed offshore accounts during the eight year period.

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