Beijing mother Han Xue had a second child last year, 10 years after her first. But despite eligibility the process was far from easy and entailed a bureaucratic paper chase.

Han, 31, felt that two children would keep each other company and provide better support to her and her husband in old age.

"As soon as my first child turned 4, we filed an application for a permit to have a second child to the government office that oversees the street where I was born," Han said.

Han and her husband were both single children and allowed, under the family planning policies introduced in the 1970s, to have a second child.

An increasing number of parents in this category are opting to do so.

Nanjing offers a prime example. Applications filed in the capital of Jiangsu province surged to 600 last year from 85 in 2007, family planning authorities said.

Meanwhile, the number of urban couples eligible to have two children has also increased as the single-child generation comes of marriageable age.

About 10,000 couples are eligible in Nanjing annually, and authorities estimate that by 2015 up to 17 percent of couples in the city will be entitled to have two children.

Already, about 15 percent of women in Nanjing who booked maternity beds for the second half of 2012 were expecting their second baby.

Since 1985, couples in the province are allowed a second child if both parents were single children.

In the province of Jiangxi, the story is much the same

In Jiujiang, one of the province's major cities, the family planning department in Xunyang district received 15 second-baby applications from March to June.

All were from couples who were themselves single children and they accounted for 31 percent of applications during this period.

"More and more couples in the category wanted a second child over the past 3 years in the district," Yu Liye, an official with the department, said.

However, couples, including Han, complained that the application process was complicated and bureaucratic.

"I don't understand why they required our parents' marriage certificate," she said.

Han's husband is from Guangdong province and does not have a Beijing hukou— residence permit — so their application took two months before approval was granted.

Documents required included residential permits, marriage certificate, ID cards, their daughter's birth certificate and a certificate to prove that the birth was permitted and the marriage certificates of both her parents and her parents-in-law.

However, compared with Wang Mei's experience, Han said she felt fortunate.

When Wang, 32, discovered that she was unexpectedly pregnant last fall, both she and her husband were excited and believed that the baby was a gift from God.

Both were single children. But getting approval tuned out to be far from simple.

"I don't have a Beijing hukou, so I had to travel for hundreds of kilometers to my hometown to get dozens of stamps on the required forms. These forms proved that I had only been married once and had only one child," Wang told Beijing Evening News.

"My parents were even asked to apply for a new version of their marriage certificate as my father's name on the original certificate is different from the name on his hukou," she recalled.

Getting all the papers in order, though, was not enough.

"The family planning department asked 10 neighbors to discuss whether I could have another baby. And their opinions were posted up in my community," she said.

When she finally got the birth permit, it was seven months after she conceived. "Our joy was dampened by the bureaucratic procedures," she said.

Yu Liye in Jiujiang confirmed the procedures and agreed that "tolerance is needed".

"It takes time to go through the procedures required to get a permit so those who want a second child should initiate the process early, say, after giving birth to the first child," he noted.

So far, all 31 Chinese provinces, autonomous regions and municipalities on the mainland have fine-tuned their policies, allowing couples who were single children to have another child. The last province to do so, last year, was the most populous, Henan.

It is important to submit applications first otherwise the couple will pay social maintenance fees despite their eligibility.

Fees vary from region to region. In Jiangsu province, they are 40 percent of the annual per capita disposable income of urban residents, which stood at 10,536 yuan (US$1,653) last year.

Yuan Xin, a professor at Nankai University's population and development institute in Tianjin said that family planning policy should be adjusted according to changing practical situations.

"Finally, Chinese couples should decide on their own how many children they want," he said.

He also ruled out any possibility that the population would explode as it was proven trend that people, particularly in cities, tended to have smaller families even without imposed limits.

A survey in August last year by the Shanghai Academy of Social Sciences and the Women's Federation of Shanghai found that 45 percent of Shanghai families have decided not to have a second child due to high costs.