Opening a tax file and filing a return do not mean you actually need to PAY taxes. You pay tax only if you have a taxable income. You will be subject to US tax on business income only if you are “engaged in a trade or business in the United States,” or “ETBUS” for short. You come under ETBUS status only if:
- you are a US citizen or green card holder,
- you have a physical presence in the USA, or
- have a dependent agent in the USA.
If none of above are applicable then you are non ETBUS. In this case, even if you serve a US client and get money into a US bank account, still that income is not subject to tax in USA.