To choose the deduction, you must deduct foreign income taxes on Schedule A (Form 1040), Itemized Deductions. To choose the foreign tax credit, you generally must complete Form 1116 and attach it to your Form 1040, Form 1040-SR or Form 1040-NR.
Choosing a credit or a deduction To choose the deduction, you must deduct foreign income taxes on Schedule A (Form 1040), Itemized Deductions. To choose the foreign tax credit, you generally must complete Form 1116 and attach it to your Form 1040, Form 1040-SR or Form 1040-NR.
Federal Withholding Tax and Tax Treaties In most cases, a foreign national is subject to federal withholding tax on U.S. source income at a standard flat rate of 30%. A reduced rate, including exemption, may apply if there is a tax treaty between the foreign national's country of residence and the United States.
The form confirms that the contractor isn't a U.S. citizen and isn't working within the United States. If both of these things are true, the contractor isn't subject to American taxes. Without this form, you must withhold 30% of your payments to foreign contractors for taxes.
The easiest way to avoid the 30% tax-withholding is to use your National Identification Number (NIN). The NIN is also usually used as a Tax ID in many countries. If you're French, this would be your INSEE code, if you hold a UK passport, it's simply called just that – a NIN.