CHINA'S most popular online payment tool, Alipay.com, said yesterday it will enforce a credit-rating system to endorse users and boost transactions.

The rating system will be backed by its own brand credibility as it classifies certain users, both businesses and buyers, with labels of "Alipay trustworthy users."

Alipay users can also check the honored business users' trading records and credibility, which are linked with their trading volume, transaction numbers and whether they have been the subject of complaint.

The first 100 companies were certified yesterday in a ceremony in Beijing. These included online game operators, communications device sellers and pharmaceutical stores.

So far there are 44 million registered users on Alipay, of whom 300,000 are businesses users.

A recent online survey by Alipay found that 70 percent of Web users regard the credibility of an online store as the most important factor in deciding whether to deal with them. Competitive prices were not so important.

PayPal.com doesn't have a similar rating, said Liu Yan, a spokeswoman for the China operation of eBay Inc.

But she said a strict verification process is enforced when businesses register on PayPal, and all transactions are monitored.

Transactions through electronic payment tools in China amounted to 14 billion yuan (US$1.85 billion) in the first quarter. Of this, nearly 10 billion yuan was through third-party Websites, according to Analysys International, a Beijing IT consulting firm.