An agreement or promise to replace legally required social insurance with cash is invalid. Article 19 of the 2025 Labour Dispute Interpretation II supports severance where the worker lawfully terminates for non-payment. After making the required contributions, the employer may seek return of the social-insurance compensation previously paid. Check the cash’s nature, contributions, termination grounds and any treaty exemption; retaining both sums is not automatic.

以现金补贴代替依法缴纳社保的约定或承诺无效。根据2025年劳动争议司法解释（二）第19条，用人单位未依法缴纳时，劳动者依法解除并请求经济补偿的，应予支持。用人单位依法补缴后，可依该条请求返还此前支付的社保补偿款。因此须区分补缴情形、现金性质、解除依据及外籍人员适用的协定，不能简单理解为两笔钱均可保留。