Find resources on this page pertaining to the international tax gap — the difference between the amount of tax that taxpayers should pay and the amount that is paid voluntarily and on time. The tax gap can also be thought of as the sum of non-compliance with the tax law. Departing aliens and the sailing permit Filing extensions and tax return preparation assistance for military personnel stationed abroad or in a combat zone Filing requirements - International individual taxpayers Foreign earned income exclusion Foreign housing exclusion or deduction Foreign Tax Credit Foreign trust reporting requirements Gifts from foreign persons Moving to or from a United States (U.S.) territory/possession Reaching out to Americans abroad Self-employment tax for businesses abroad Tax treaties can affect your income tax Taxation of international pensions and annuities Taxation of nonresident aliens U.S. citizens performing services in foreign and international airspace U.S. tax withholding on effectively connected income allocable to foreign partners U.S. tax withholding on payments to foreign persons Withholding of tax on dispositions of U.S. real property interests The tax gap - News, facts, figures and a fact sheet series on the tax gap in general.