Foreign online sale and income tax?

It depends. The tax implications of selling on a foreign online platform while shipping merchandise from the U.S. depend on several factors, including where your business is legally established, where the income is sourced, and whether tax treaties apply.

1. If you are a U.S. citizen, resident, or business entity, you are generally required to pay U.S. income tax on worldwide income, including profits from foreign sales.
2. The IRS considers income to be U.S.-sourced if the sale is made within the U.S. or if the goods are shipped from the U.S.

You may need to check the tax treaty of the country you are shipping to to see if your income is taxed there or not.

United States income tax treaties - A to Z