People in China who use Alipay will start to pay the platform for transferring money on October 12th. How big of an impact will the charges have on China's growing number of mobile payment users?

Payment platform Alipay will charge a 0.1 percent service fee for users who transfer more than 20 thousand yuan. The new rule takes effect on October 12th.

However, the rule will only apply to transfers of money from the platform to debit cards. Some of the more frequently used ways of transfers, such as offline payments, credit card repayments and buying wealth management products on the platform, will not be affected.

"We recommend people to use their money on our platform more on consumption and credit card repayments," said Zhu Jian, director, Customer Communications, Alipay.

Experts say that judging by the growth of the mobile payment market, it's about time for the move. The sector had been growing at staggering triple digit rates in the past several years but the speed of expansion seemed to be plateauing into the first quarter of 2016.

"Mobile payment's growth is becoming rational. Companies have passed the phase where they need to educate users. This is a good time to start charging money," said Ma Tao, director, Financial Industry Research, analysts.

Alipay is not the first. It's main rival, Wechat's payment platform, started to charge users in March. Experts say the reason why Wechat moved sooner was because it is a social app while Alipay is not.

"When you're a social app, the transfer of money between people is very frequent. For Wechat, 60 percent of transfers were between users, and that is below 30 percent for Alipay. So the operation burden is higher for Wechat," Ma Tao said.

That administrative burden translates into high costs. Experts say that as growth speed likely continues to slide, the two payment platforms could come up with more ways to generate revenue.