@HalfPriceDigi, don't forget to prepare and file Form 5471 for your UK company. Screw that up and it is an automatic $10,000 penalty.

(Disclosure: international tax lawyer; have fought this battle with the IRS before).

And yes. The banking problem is the hard problem to solve.

In both directions. U.S. banks can be giant poopy-heads. Bank of America just closed the account of a foreign client of mine who had banked with them for 33 (!) years. "We don't have to give you a reason, and we are sending you a check for your money." The second such client to experience this. Both are moving to Citibank, for what that's worth to you.