Can an employer in the state of California have a policy that requires employees to speak only English while at work?

Under the provisions of the California Fair Employment and Housing Act (FEHA), employers with at least five employees generally cannot limit or prohibit the use of any language in the workplace, except in rare circumstances when they can demonstrate a legitimate business necessity do so. A legitimate business necessity is defined as follows:

• There is an overriding and legitimate business purpose that makes language restriction necessary for the safe and efficient operation of the business.
• The language restriction effectively fulfills the business purpose it is supposed to serve.
• There is no existing alternative practice to the language restriction that would accomplish the business purpose equally well with a lesser discriminatory impact.

Additionally, employers must notify employees of any situations and times when any language restriction must be followed, as well as the consequences for failure to comply with a restriction. As with any workplace policy that restricts or imposes on employees, employers with English-only or other language restrictions should consult with legal counsel to ensure that the policy is nondiscriminatory and legally enforceable.

Source: Government Code 12951