Federal and State law do not conflict in this regard: if an employer hires an undocumented worker in violation of federal law, the employer is required to compensate the person in a manner consistent with state law for work they actually perform. Here, neither Lopez’s immigration status nor the barter arrangement with his employer provided grounds to deny his wage claim for work already performed. The Court provides guidance about an employer’s record-keeping burden and about how to assess the admissibility of evidence of an invalid SSN in wage and hour cases.