The personal information of turnstile jumpers in the Shanghai metro will be transferred to a credit-rating database starting on Wednesday.

The database, which contains a record of enterprises and individuals, is expected to be launched this summer with the aim of clamping down on dishonest practices across the city.

More than 30 non-paying metro commuters were caught on Wednesday morning at the ticket gate of Xinzhuang station on subway lines 1 and 5.

Violators are likely to find their credit damaged in the future, making it harder to get a loan, according to Zhou Guoxiong, a Shanghai legislator and Party chief of the city's economy and information commission. He said the database has been growing for three years and the official launch is expected in June.

Shanghai Morning Post reported that turnstile jumpers cost the metro system roughly 10 million yuan ($1.6 million) a year.

An estimated 0.16 percent of the 6 million daily passengers never pay for tickets, while the percentage of freeloaders in Shanghai's large metro stations reaches 2 to 3 percent, the newspaper reported.