Can an F1 student working on OPT with a STEM extension earn unrelated self employed income from a foreign employer?
From tax perspective, any income you earn for services performed while you're in the US is US-sourced. The location of the person paying you is of no consequence. From immigration law perspective, you cannot work for anyone other than your employer as listed on your I-20. So freelancing would be in violation of your visa, again - location of the customer is of no consequence.
"I did a little research and found this article from 2006 by a Villanova law professor, titled ""No Thanks, Uncle Sam, You Can Keep Your Tax Break"".  The final paragraph of the article says: Under these circumstances, it is reasonable to conclude that a taxpayer is not required to claim a allowable deduction unless a statutory provision so requires, or a binding judicial precedent so specifies. It would be unwise, of course, to forego a deduction that the IRS considers mandatory such as those claimed by self-employed individuals with respect to their self-employment,    whether for purposes of the self-employment tax or the earned income tax credit. Until the statute is changed or some other binding authority is issued, there is no reason taxpayers who wish to forego deductions, such as the dependency exemption deduction, should hesitate in doing so. (The self-employment tax issues in the quote cited by CQM are explicitly discussed in the article as one of a few special kinds of deduction which are mandatory.) This is not a binding statement: it's not law or even official IRS policy.  You could never use it as a defense in the event that this professor turned out to be wrong and the IRS decided to go after you anyway.  However, it is a clear statement from a credible, qualified source." You need to set your status as self-employed the day you started online work. If that date is a little ambiguous (as is usually the case with online business), you can start with the day you first made any money. Yes, you can deduct expenses from your revenue. But you have to be sure that the expenses were purely business related.  This is how it goes: You inform HMRC about the day you started work. HMRC will assign you a UTR (Unique Tax Reference) number. Depending on how much you make you might or might not need to pay Class 2 NI contributions. You'll need to tell HMRC how much you expect to earn in the current tax year. Finally, you'll need to complete a Self-Assessment at the end of the tax year. I highly recommend setting up a business banking account. Here is a link that discusses being part-time self-employed in the UK. Your taxable income is your total income from however many sources of income you have. If you are in employment and doing self-employed job at the same time, your taxable income will be a combination of both incomes.  For example if in employment you make £10000 and self employed you make another £10000 - your total income is £20000 and this is your taxable income.  And even if your self-employed job does not bring you more than personal allowance, how would HMRC know that without you filling-in tax return? "If you have income - it should appear on your tax return. If you are a non-resident, that would be 1040NR, with the eBay income appearing on line 21. Since this is unrelated to your studies, this income will not be covered by the tax treaties for most countries, and you'll pay full taxes on it. Keep in mind that the IRS may decide that you're actually having a business, in which case you'll be required to attach Schedule C to your tax return and maybe pay additional taxes (mainly self-employment). Also, the USCIS may decide that you're actually having a business, regardless of how the IRS sees it, in which case you may have issues with your green card. For low income from occasional sales, you shouldn't have any issues. But if it is something systematic that you spend significant time on and earn significant amounts of money - you may get into trouble. What's ""systematic"" and how much is ""significant"" is up to a lawyer to tell you." No, it's not possible. Even if you had no deduction or credits, your federal tax on $16,604 would be: $9075 @ 10% = $907.50 +  $7529 @ 15% = $1129.35 = $2036.85 That assumes you are filing as single. There must be more to the story.  Typo in your income numbers?  Also, what do you mean by a self-employment tax deduction? Maybe update your question to include a breakdown of everything you entered? Edit: As noted in Loren's answer, it seems that it is indeed possible in at least one case (self-employment taxes). "Even though you will meet the physical presence test, you cannot claim the FEIE because your tax home will remain the US. From the IRS: Your tax home is the general area of your main place of business, employment, or post of duty, regardless of where you maintain your family home. Your tax home is the place where you are permanently or indefinitely engaged to work as an employee or self-employed individual. Having a ""tax home"" in a given location does not necessarily mean that the given location is your residence or domicile for tax purposes.   ...   You are not considered to have a tax home in a foreign country for any period in which your abode is in the United States. However, your abode is not necessarily in the United States while you are temporarily in the United States. Your abode is also not necessarily in the United States merely because you maintain a dwelling in the United States, whether or not your spouse or dependents use the dwelling.   ...   The location of your tax home often depends on whether your assignment is temporary or indefinite. If you are temporarily absent from your tax home in the United States on business, you may be able to deduct your away from home expenses (for travel, meals, and lodging) but you would not qualify for the foreign earned income exclusion. If your new work assignment is for an indefinite period, your new place of employment becomes your tax home, and you would not be able to deduct any of the related expenses that you have in the general area of this new work assignment. If your new tax home is in a foreign country and you meet the other requirements, your earnings may qualify for the foreign earned income exclusion.   If you expect your employment away from home in a single location to last, and it does last, for 1 year or less, it is temporary unless facts and circumstances indicate otherwise. If you expect it to last for more than 1 year, it is indefinite.   If you expect your employment to last for 1 year or less, but at some later date you expect it to last longer than 1 year, it is temporary (in the absence of facts and circumstances indicating otherwise) until your expectation changes. For guidance on how to determine your tax home refer to Revenue Ruling 93-86. Your main place of business is in the US and this will not change, because your business isn't relocating. If you are intending to work remotely while you are abroad, you should get educated on the relevant laws on where you are going. Most countries don't take kindly to unauthorized work being performed by foreign visitors. And yes, even though you aren't generating income or involving anyone in their country, the authorities still well may disapprove of your working. My answer to a very similar question on Expatriates." Business Apprentice is internship. That is not what is applicable for you. You're a visiting professor/researcher, which falls under Article 22, so you don't get the standard deduction. My graduate stipend was wage income so I could make Roth IRA contributions.   Don't lose the year; you can withdraw nominal contributions if needed.  What you choose is less important than making the contribution.