The law says:
Employment Services Act. Promulgated on May 8, 1992.
Chapter 5
The Recruitment and Supervision of Foreign Persons
Article 53
An employer shall not behave in the following manners:
Employ or continuously give employment to foreign persons without permission, or when the permission has been invalidated,
Employ foreign persons under his own name to work for other people,
Employ or continuously give employment to foreign persons for whom others have applied for work permits,
Assign foreign persons to engage in work other than that denoted in the permit.
Article 54
In case any of the following conditions prevail, the foreign person’s work permit shall be partially or completely revoked:
Working for an employer not certified in the work permit,
Engaging in work not mentioned in the work permit,
The existence of any of the situations specified in Article 52,
Refusal to have regular physical check-ups during the period of employment, or if the physical and/or mental competence of the employee is inadequate for the work assigned, or if the employee suffers from an infectious disease stipulated by act or death.
Violation of the demands prescribed in accordance with paragraph 2 of Article 44, Article 45, Article 46, or paragraph 1 of Article 47, causing serious consequences,
Violation of other laws or regulations of the Republic of China, causing serious consequences.
Any foreign person whose work permit has been revoked as denoted in the previous paragraph, shall be compelled to leave the country immediately and shall not be allowed to seek work in the Republic of China.
So in short, you can only have one work permit, and only work for one employer.
Regards
John
taiwanteacher.bizland.com
taiwan_teacher@hotmail.com
Kaohsiung