A report by China's State Post Bureau confirmed that the country overtook the United States and had the highest express delivery volume in the world last year.

Some 13.96 billion items were handled and delivered by express delivery companies in China in 2014, a 51.9 percent increase over the previous year, with a daily volume of 38.25 million items. Delivery services within the country had 204.54 billion yuan ($32.95 billion) in revenue, a 41.9 percent increase over the previous year.

Express delivery companies also improved their service as the market surged, with fewer complaints about delivery received last year. According to the country's postal service complaint center, 719,000 complaints were made, of which 239,000 were valid. Delayed, lost or damaged packages and dissatisfaction with service were the major problems and 96.1 percent of complainants were satisfied with the center's response.

SF Express received the highest customer satisfaction rating, followed by EMS and ZTO Express. The following are the top 10 courier services in China in terms of customer satisfaction.

No 10 UC Express

The UC Express stand in Beijing, May 29, 2013. [Photo/IC]