If you are working abroad for a foreign employer, you may have to pay estimated tax, since not all foreign employers withhold U.S. tax from your wages. Your estimated tax is the total of your estimated income tax and self-employment tax for the year minus your expected withholding for the year.
When you estimate your gross income, do not include the income that you expect to exclude. You may subtract from income your estimated housing deduction in figuring your estimated tax liability. However, if the actual exclusion or deduction is less than you expected, you may be subject to a penalty on the underpayment.
Use Form 1040 ES, Estimated Tax for Individuals, to estimate your tax. The requirements for filing and paying estimated tax are generally the same as those you would follow if you were in the United States. If your tax year is the calendar year, the due date for filing your income tax return is usually April 15 of the following year.
You may be able to have your employer discontinue withholding income tax from all or a part of your wages. You can do this if you expect to qualify for the income exclusions under either the bona fide residence test or the physical presence test.
U.S. payers of benefits from employer deferred compensation plans (such as employer pension, annuity, or profit-sharing plans), individual retirement plans, and commercial annuities generally must withhold income tax from the payments or distributions. You can choose exemption from withholding if you provide the payer of the benefits with a correct taxpayer identification number and a residence address in the United States or a U.S. possession, or certify to the payer that you are not a U.S. citizen or resident alien or someone who left the United States to avoid tax.
For rules that apply to non-periodic distributions from qualified employer plans and tax-sheltered annuity plans get Publication 575, Pension and Annuity Income (Including Simplified General Rule).