If you fail to file a tax return, you may be subject to civil and criminal penalties. While criminal penalties may not be enforceable once you have left the United States, civil penalties could potentially be enforceable on property you own that is left behind in the United States.
There are different civil penalties for filing late, fraud, paying the tax late, and accuracy problems. The civil penalty for filing late is based on the tax not paid by the due date. The penalty is usually 5% for each month or part of a month that a return is late, but not more than 25%. In addition, if you owe income tax, the IRS has ten years from the date the tax is assessed to collect the tax. But if you fail to file a tax return, the ten-year period for collection does not start running. In this case, the IRS has an indefinite time to collect the owed taxes. Failing to file tax returns also may have negative consequences should you seek to immigrate to the United States again in the future.
Additionally, failure to file taxes when required may impact the naturalization process. Eligibility for naturalization requires demonstration of good moral character. Applications for naturalization ask specific questions about filing taxes. If U.S. Citizenship and Immigration Services (USCIS) believes that you have avoided your tax obligations in any way, it can deny the application based on the good moral character requirement.[1] In recent years advocates have reported closer scrutiny by USCIS of tax compliance.