Just as the Internal Revenue Service bolsters its international enforcement capabilities and activities, it is also phasing out its voluntary disclosure program.

The IRS said it is ramping down the 2014 version of its Offshore Voluntary Disclosure Program and will close it entirely on Sept. 28. That amounts to a last call for individual or corporate taxpayers who know they have unresolved compliance problems related to unreported foreign financial assets and failures to file appropriate returns. Voluntary disclosure generally results in reduced penalties compared to actions that are initiated by the IRS, thus incentivizing taxpayers to come forward voluntarily.