20 to 25 working days. According to the inquiry of China Travel Service. Com, the guarantee letter of Changzhou provident fund loan can be completed in 20 to 25 working days. Changzhou, also called Longcheng for short, is a prefecture-level city in Jiangsu Province, one of the central cities in the Yangtze River Delta region of China, an advanced manufacturing base and a famous cultural tourism city approved by the State Council.