China will relax customs regulations for companies registered in its Shanghai pilot Free-Trade Zone (FTZ), allowing a firm to declare goods at customs anywhere in China for the first time, state media quoted a Shanghai official as saying on Monday.

The reforms, which come into effect on Tuesday, will allow top-tier firms with their operational headquarters registered in the FTZ to declare their goods at customs anywhere in China, the official Xinhua news agency reported.

"This will give them an opportunity to develop their access to the entire country rapidly," said Li Feng, an official at the Shanghai customs business management office, Xinhua reported.

The move targets logistics firms and multinational corporations, Li said, adding the evaluation for top-tier firms will be the responsibility of the FTZ and not that of Shanghai customs.

About 120 top-tier firms will be selected for a trial where the FTZ will aid the companies in clearing customs between China and other countries and regions, as well as help improve the companies' international competitiveness.

From Tuesday, the customs authority will also publish a regular public directory for credit information of companies operating through Shanghai FTZ customs. This is intended to strengthen supervision firms and encourage honest conduct.