If you had your business in Peru, and only accepted payment for your services with Peruvian Nuevo Sol (their currency), I don't think that you could be deemed a

If you had your business in Peru, and only accepted payment for your services with Peruvian Nuevo Sol (their currency), I don't think that you could be deemed a business operating in the US if someone from the US signed up, but was charged in Nuevo Sol, with their bank doing the currency exchange. I could be wrong though, so don't take my word. If you accepted US dollars (and then exchanged them locally in Peru, or kept them), say through PayPal or a US based Credit Card Merchant, then I could almost guarantee that is enough to deem your business as operating in the US.