The policy was expanded from A-level or above to cover B-level businesses, the GAC said.
China's custom regulations divided foreign trade businesses into five levels, namely AA, A, B, C and D, considering their compliance with customs laws and regulations, trade volume and management.
The policy means qualified enterprises can declare cargos to local customs where they were registered before port entry or departure.
Zhang Guangzhi, the GAC spokesman, said that increasing domestic businesses will become more competitive with convenient logistics channels and easier custom policies.
The GAC started policy reforms on Nov 1 in 2013, and the easier customs policy helped increase monthly freight volume by 5.77 percent to 19.14 million tonnes, Zhang said.