Dear boss, the lawsuit against overtime pay was successful after the payroll was signed. According to the Notice on Determining Relevant Matters of Labor Relations and the provisions of the Labor Social Development (2005) 12, the employer has not signed a labor contract with the employee, and when determining the existence of labor relations between the two parties, it can refer to the following documents: (1) wage payment vouchers or records (employee wage roster) and pay various social insurance premiums; (2) The work permit, service certificate and other documents that can prove the identity issued by the employer to the employee; (3) Employment records such as Registration Form and Application Form filled out by employees; (4) attendance records; (5) Testimonies of other workers, etc. Therefore, Zhang Can applied to the labor department for arbitration. If he refuses to accept the arbitration, he can bring a lawsuit to the people's court and ask the relevant departments to protect your legitimate rights and interests. Second, who should bear the burden of proof of the payroll? In many labor and wage disputes, the two sides often argue about whether the unit has paid the wages and who will bear the burden of proof. However, according to the relevant judicial interpretation in China, the burden of proof whether the salary has been paid should be borne by the employer. China's "Interim Provisions on Wage Payment" stipulates that an employer may entrust a bank to pay wages on its behalf. The employer must record in writing the amount and time of employees' salary collection, the name and signature of the recipient, and keep it for more than two years for future reference.