Well yah, you don't call it that.

You select your SICC number when you sign up as a new business and this designates your IRS classification. You classify as a "security contractor" and define your services clearing on a webpage.

Then, send a receipt to the customer for services rendered.

If you contract enough - you have to learn legal and state law stuff.

Especially with corporations, they value getting their money back or getting a service. They are less likely to tell on you - but they do have their own people. lol