"This is not acceptable because financial flow in P2P lending is supposed to be point to point, so each account should be kept separate," Sun says.
Another irregular practice in China is for P2P firms to promise lenders that they will receive the money they have invested, he says.
Such a practice is against industry practice because P2P companies are not traditional banks, but instead are intermediaries that collect fees from brokering loans between borrowers and lenders. Their role is to facilitate information disclosures and it is the responsibility of lenders to assess and accept the risks of default.
But because there is no regulator, many P2P firms use this practice to win clients. Sometimes they use new lenders' money to repay old lenders in cases of default, which is an illegal practice in P2P lending, Sun says.
Sun's words are echoed by Hua Meng, CEO of the Chinese P2P company Cashlai.com, who is also a researcher at the Chinese Academy of Social Sciences.
Hua says the Chinese government already has expressed the intention to regulate the P2P industry, having recognized its important contribution to the Chinese economy.
"The UK's P2P market regulation is great because it focuses on consumer protection, which is important for the long term growth of the industry," Hua says.
Scott Murphy, who works in policy and consumer affairs at RateSetter, a UK P2P company, says he believes Chinese firms can also learn from the UK firms' practice of creating a provision fund to help ensure secure returns for the lender.
The fund is drawn from a risk-weighted fee that lenders pay, and is used to cover defaults automatically should they occur. He says since RateSetter's founding, no lender has lost any money due to defaults.
Murphy adds that there are many lessons the UK's P2P companies can learn from China, and an example of this is offline lending, which seems to reach a wider base of users including those who are less Internet-savvy.
"The China route is meeting the needs of a wider group of consumers," Murphy says. "We should be looking at the examples in the States and in China to see if this is something we'd like to see in the UK."
Sun says China's P2P market has the potential to become world leading, because it has grown rapidly over a short time and also the demand for borrowing from Chinese SMEs is so great.
"I expect Chinese P2P firms to make a significant contribution to the importance of P2P lending globally," he says.