Starting a UK Subsidiary

I am a US company (S-corporation) and I need to start processing payments through the UK for Europeans. What is the easiest way to set up a subsidiary or part of the company over in the UK?

All employees and locations are currently based in the US but I have the ability to get mailing addresses etc over there through close contacts who could join the company / board.

Would it make sense to do a subsidiary or a completely new company? Thanks

I had a contact who set up a Limited company in the UK- I don't think that it was more difficult than setting up a basic corporation in the US. It just required a Memorandum and Articles of Association and some other paperwork.

ETA: I don't understand your follow-on question- a subsidiary IS a completely new company, owned by your existing company.

Setting up a limited company in the UK is very easy -- the fastest way is to find an "off the shelf" company that's already been registered, purchase it outright, then change the name.

Any reasonable accountant will be able to do this quickly and relatively cheaply. You'll need a "registered office address" which is a physical location (no PO Box numbers) where documents can be effectively served -- again, accountancy firms can host this for you, for a fee.

Once you have the company it will need to send audited accounts to Companies House, and it will also need to file appropriate tax returns and accounts to HM Revenue and Customs. Again, this is work best outsourced to a local accountant.