Yes there are higher standards.

Here's a quick blurb from a law firm blog, notice the "acts at its peril" language which is not the standard for private citizens contracting together:

"Authority Issues. Contract awards and contract modifications may be made on behalf of the government only by duly appointed contracting officers acting within the limits of both available funding and their delegated authority. This public policy principle of limited authority is strongly supported in the law. To the extent that a company incurs costs based upon the directions or promises of government persons without this essential authority, the company does so at its financial risk. Moreover, the contractor has the responsibility to know the scope of authority of the government official with whom it deals, and acts at its peril."

https://www.crowell.com/en/insights/publications/the-risks-a...