In the United States, taxes are only charged if you make a certain amount of money in a state. If you're below the threshold, there's no need to charge tax. However, you still need to pay taxes on money you make in the US, which depends on your filing type, earned amount, and several other factors. Each state has a different tax rate, and different tax laws for digital purchases. Tax charges like tariffs apply only if you import goods that are over $800. Underneath that threshold, and you don't have to pay a tariff. If you're a Canadian based company operating in the United States, you have to file documentation for a non-domestic business. That may or may not come with it's own set of taxes. Generally speaking, you only need to give your EIN for some payment systems because taxes are handled separately. For instance, if your net revenue is 1MIL in Pennsylvania, but you only earned 50K in New York, you only charge sales tax in Pennsylvania. You have to register your business in Pennsylvania, and file some documents to collect sales tax legally. I recommend consulting with a business lawyer to get it right. They can help you sort it out. I do not recommend just going on advice given on here.