Relevant for non-residents / foreign owned LLC :

https://onlinetaxman.com/us-llc-tax-haven-for-foreigners/

If you don’t have a dependent agent that substantially furthers your business in the US and don’t have an office in the US, you are not subject to US tax. Even if the LLC generates income in the US, the income is not taxed in the US.

Furthermore, if you reside in a country with an applicable tax treaty with the US, then you would not be subject to US tax. Since you reside in your tax home, you can claim you operate a “permanent establishment” (e.g., an office or other fixed place of business) in your home country.