A one way NDA protects information flowing in one direction, from you to the other party. A mutual NDA protects both sides, which you need whenever you will each be sharing sensitive information.

Most NDAs last two to five years after the business relationship ends, which covers the typical shelf life of ordinary business information. Genuine trade secrets are the exception, and they can be protected for as long as they stay secret, even indefinitely.

Technically you can use the same NDA for employees and contractors, but it is usually a mistake. The two worker types touch different kinds of information, face different legal rules, and need different clauses on ownership and duration.

If you break an NDA, the other party can sue you for breach of contract, ask a court to recover money damages, and in many cases get an injunction to stop you from sharing anything further. Depending on the agreement and your state, you could also be on the hook for their legal fees.