Zopa took 10 years to do its first £1 billion - it will hit its second in under 2 years

Peer-to-peer lending - where savers cut out banks and lend directly to people and businesses at better rates - is growing explosively in the UK and the latest company to underline this is Zopa.

The London-based company just announced that it hit a big lending milestone after 10 years - £1 billion ($1.5 billion).

The peer-to-peer (P2P) lender was the first of its kind in the UK when it opened its doors way back in 2005. Its platform lets savers lend their money directly to individuals (as opposed to businesses like, say, Funding Circle does.)

Lenders typically get an annual interest rate of 5%, better than banks' offers to savers.

While £1 billion is a big milestone to hit, what's perhaps more interesting is how quickly Zopa expects to hit its next billion.

Co-founder and CEO Giles Andrews told Business Insider: "We hope to do £1 billion of lending in the next calendar year from January. I would estimate we get to our second billion towards the end of next year."

10 years to do the first £1 billion - less than 2 to do the next. That's a crazy growth curve.

Zopa is on track to lend over £550 million ($859 million) this year, more double 2014's total of £265 million ($414 million). Revenues are also forecast to double this year.

Andrews says: "We should slightly more than double this year and I hope we double again next year - that's dramatic."

Zopa is hardly an outlier either. The chart below from industry website AltFi and investment bank Liberum shows UK peer-to-peer lending has exploded in recent years. The pair estimate £4.2 billion ($6.57 billion) has been lent through peer-to-peer in the UK to date (meaning Zopa has done around a quarter of the overall total.)

"It feels like we're becoming more mainstream," Andrews says. "We've met the financial needs of over 200,000 people and been able to give them a better deal, either on their borrowing or their lending/investing."

Zopa has doubled its headcount to 110 over the past year and signed deals with big names like Metro Bank and Uber, which took it into car financing for the first time. Andrews says Zopa is exploring other partnerships, with more announcements expected this year.

The company is also looking at launching other products. Andrews signalled Zopa was thinking about a property lending operation, saying Zopa would look at "adjacent lending products, which we would consider with the right funding. We wouldn't start up a small mortgage business, we either do it properly or not at all."

Andrews says: "The plan for the next year is to do more of the same. The vision for five years is a broader offering either geographically or on product, or both."