we[1] are a fintech startup based in london... There are a couple of others too - Seedrs are based in Shoreditch, MarketInvoice is in W1, but a few of the others are slightly further out (e.g Nutmeg is in Vauxhall from memory, we're in Crouch End.)

Edit: a few I forgot - and I'm surely missing several more - Zopa (W1), Abundance Generation (W12), and of course - Wonga (W1)...

[1] http://www.rplan.co.uk