The I-9 form (also known as the Employment Eligibility Verification form), is one that every business owner should be familiar with — you're required to fill it out for all your employees. But construction attorney D.S. Berenson of Johanson Berenson LLP says that the biggest problem he encounters with this form is that many contractors just don't use it.

You don't have to submit the I-9 to the government, but you are required to keep it for three years after an employee's date of hire or one year after his employment ends, whichever comes later. However, in the event of an I-9 audit, you will have to make these documents available to Immigration and Customs Enforcement (ICE) —and with the amount of immigrant labor in the construction industry, as well as the recent interest in immigration reform, you can expect more audits than ever before. Fines are substantial, and non-compliance can become criminal in the case of repeat infractions.

To that end, here are some of the things you need to know about the I-9. Employees complete Section 1 of the form, so we've omitted it for space reasons. For the full form and official instructions on filling it out, please visit www.uscis.gov/graphics/formsfee/forms/i-9.htm.