Does not pay social security at work count as seniority?

Legal analysis: Yes. The length of service can be calculated from the time when employees establish labor relations with their units, with wage income as the main source or all sources. However, the only legal significance of calculating social insurance benefits is continuous service and payment service. The length of service marks the length of employees' working hours, and also reflects employees' contribution to society and enterprises and their level of knowledge, experience and technical proficiency. That is, the continuous length of service includes not only the continuous working time in this enterprise, but also the working time that can be calculated by the merger of the two work units. If there is no merger, the continuous length of service is the length of service of the enterprise.

Legal basis: Notice of the Human Resources and Social Security Bureau on the determination of the continuous length of service of some newly recruited (hired) personnel in government agencies and institutions. Persons who were originally employed in state-owned enterprises, urban collective enterprises and non-public-owned units and participated in the basic old-age insurance for employees of urban enterprises, after being registered (employed) as official staff of government agencies and institutions, their payment years and working years after being registered (employed) as official staff of government agencies and institutions are calculated as continuous service. Without purchasing social security, according to the spirit of the above documents, this period of working years cannot be regarded as continuous working years.