Wow, just had email invitation to join the Stripe UK.
As of today, you can accept Visa and MasterCard transactions. You can choose to accept payments denominated either in pounds, euros or US dollars, with American Express transactions coming soon. (Note that you can only accept USD if you have a US-based bank account.) If you need to accept multiple currencies, you'll need to create multiple accounts. All our standard docs and features apply -- jump in at https://stripe.com/docs.
Additionally, if you're creating a marketplace, store builder, invoicing system, or anything else that helps users get paid, you can use Stripe Connect to let your users accept credit cards instantly by having them connect their Stripe account -- find out more at https://stripe.com/connect