According to many opinions, “each have” is only more formal than “each has”, so supposedly both are correct. However, and according to the same opinions, if it precedes the compound subject, the singular should be used, as in: “Each boy and girl has reasons to be unhappy.”

Do you use has or have after each?

The traditional choice is a singular verb (has) to agree with each, but a writer might choose the plural verb (have) because the reference seems to be to two things: your firm and the agency. Or, perhaps, the writer might choose have to go with you.

Is it each of us has or have?

The Associated Press Stylebook says "each" calls for a singular verb, so the speaker should have used "has." Webster's Dictionary of English Usage says, "The rule of thumb from the 18th century on has been that 'each' takes a singular verb. This is the usual case in modern practice."