Note: to use the 公章 you must email Lei and CC Mary for approval. Please explain clearly in the email why you need it. After Lei approves the request via email, you can go to Mary with your documents, and Mary will stamp the documents for you.
所需材料
1. 外国人来华工作许可延期申请表:在线填写打印,申请人签字后,加盖用人单位公章或经单位授权部门公章上传至系统。原件(电子/纸质1份)。
2. 聘用合同或任职证明。应提供中文合同,应由申请人签名并加盖单位公章,不得涂改。原件\复印件(电子/纸质1份)。备注:聘用合同应包括工作地点、工作内容、薪酬、来华工作时间、职位、盖章页(签字)必要内容。任职证明适用执行政府间、国际组织间协议或协定人员、各类驻华代表处首席代表及代表及境外合同服务提供者(代表处需提供代表证原件)。
3. 申请人护照及有效工作类居留许可。护照(或国际旅行证件)首页及工作居留许可信息页。原件(电子/纸质1份)。
4. 《外国人工作许可证》。包括现行有效期内的《外国专家证》和《外国人就业证》。原件(电子/卡证1份)。
This information is from the China Law Blog.
The most important factor in keeping your work permit is getting a letter of release from your current/old employer company. Technically, as long as the employee has not violated its contract, the employer company is required to provide this release letter. However, as you can imagine, people often have problems obtaining this letter when they don’t have a good relationship with the company they are leaving. I am not sure how it works, but it seems that there are ways that the company can strip you of your permit so you are left with 30 days to leave the country. Other sticky situations include companies that posses employee permits or even passports.
However, assuming there are no serious issues, the process seems relatively straightforward. I spoke with a few visa agents and they provided me with a list of documents that I needed to collect:
All of the visa agents assured me the whole process is usually very easy. I asked for quotes and one person said it would take around two and a half weeks and would cost RMB 2,500, which includes government fees, however much that may be.