like all laws, there are loopholes but i don t see any reason why it would be illegal as long as you are paying american taxes for your american business.but i am no lawyer, maybe you should make the right enquiries
Tax laws between the US and the UK are controlled by a Tax Treaty signed in 2002. The one before that was in force from 1975. The tax treaty prevents double taxation, which you would be subject to if you did business in the US and were physically present.You should contact a tax advisor who is comfortable dealing with international issues and with the US-UK Tax Treaty. The Big Four accounting firms will do this for you, but it will cost a lot -- thousands of pounds. (The Big Four are Pricewaterhouse Coopers (PwC), Deloitte and Touche, Ernst Young, and KPMG.)You can also try a medium-sized international tax advisor. They will charge hundreds of pounds for an hour-long visit. As an American living and working in the UK and sometimes the US, I use a good firm based in Windsor. They are not the ones who do my taxes. They just set up my tax strategy for the next several years.Let me know if you need this corporation s contact details.
I think it should be ok as long as you pay taxes earned in their borders. You should check all the relevant facts.