When an employer is the petitioner, the beneficiary can only work for the employer. If the beneficiary wishes to work for more than one employer, they may either file concurrent O-1 petitions or consider filing with an agent petitioner. An agent petitioner allows the beneficiary to work for more than one employer, provided that each employer signs a contract with the petitioner. A petition filed by an agent is subject to additional evidentiary requirements, listed under 8 CFR 214.2(o)(2)(iv)(E). The evidence required depends on whether the agent is filing as an agent performing the function of an employer; as a person or company in business as an agent and filing for multiple employers; or as an agent for a foreign employer.