If a company fires you without 30 days’ notice, it must pay an extra month’s salary

Cost: No cost at all.
In plain terms: If a company terminates your employment without giving 30 days’ written notice, it must pay you an additional month’s salary on top of the standard compensation. This is commonly referred to as “N+1.” When negotiating, make sure this extra month is listed separately so the company doesn’t include it in the base amount “N.”
Benefit: Under labor law, when an employer ends a contract under this provision, there are two permissible options: either provide 30 days’ written notice to the employee, or pay an extra month’s salary and then terminate the contract. If the employer wants you to leave immediately, it must pay this additional month’s wage. This extra payment is known as “notice pay” and is calculated separately from “N.”
Evidence grade: A
Sources:全国人大常委会 (2007). 中华人民共和国劳动合同法（2008 年 1 月 1 日施行）（第三十六、三十九、四十、四十一、四十六、四十七、八十七条）. http://www.gov.cn/gongbao/content/2007/content_711013.htm；国务院 (2008). 劳动合同法实施条例（国务院令第 535 号）第二十条：「用人单位依照劳动合同法第四十条的规定，选择额外支付劳动者一个月工资解除劳动合同的，其额外支付的工资应当按照该劳动者上一个月的工资标准确定」. http://www.gov.cn/gongbao/content/2008/content_1107604.htm
Notes: Consequently, the typical outcome of a lawful termination under these circumstances is “N+1.” During negotiations, keep the base compensation “N” and the extra month distinct to prevent the employer from bundling them together.