Validity Period of Residence Permit

在中国境内居留的外国人申请延长居留期限的，应当在居留证件有效期限届满30日前向居留地县级以上地方人民政府公安机关出入境管理机构提出申请，按照要求提交申请事由的相关材料。经审查，延期理由合理、充分的，准予延长居留期限；不予延长居留期限的，应当按期离境。

外国人居留证件登记事项发生变更的，持证件人应当自登记事项发生变更之日起10日内向居留地县级以上地方人民政府公安机关出入境管理机构申请办理变更。

Foreigners residing in China who intend to extend their stay must submit an application to the local public security bureau's entry-exit administration office at the county level or above at least 30 days before their residence permit expires. Relevant documentation justifying the need for an extension must accompany the application. Approval for the extension will be granted if the reasons presented are considered adequate and justifiable upon evaluation. Failure to meet the criteria will necessitate timely departure.

Should there be any alterations to the registration particulars specified on a foreigner's residence permit, the permit holder must notify the local public security bureau's entry-exit administration office at the county level or higher within 10 days of the modification taking effect.