The tests for determining whether a business is a joint employer vary, depending on which law applies. That means there are different tests under federal labor law, wage and hour law, and employee benefits law, to name a few. There are also different tests under different states’ laws.
Further complicating the analysis, there are even different tests when applying the same law — depending on where you live.
Yes, you read that right. Even though the Fair Labor Standards Act (FLSA) is a federal wage and hour law that applies across the country, federal courts in different states use different methods for determining whether a business is a joint employer under that single law.