If your employee is a Singapore Citizen / Singapore Permanent Resident (PR), the resignation must be accepted as they have the right to resign at any time either by serving the required notice period or by compensating the employer with salary-in-lieu. Under Section 108 of the Employment Act, failure to allow an employee to leave the service is an offence. The employer is liable on conviction to a fine not exceeding $1,000 to imprisonment for a term not exceeding 6 months or both.