The U.S. government strategy to clamp down on illegal immigrant workers has been focused for the last two years on so-called I-9 audits that target employers rather than large-scale raids that net lots of employees .

Upscale burrito chain Chipotle Mexican Grill Inc told Reuters on Friday that a U.S. Immigration and Customs Enforcement (ICE) probe into its hiring practices is widening. These I-9 audits, experts say, are a wake-up call to the fast food and restaurant industry that relies heavily on immigrant labor.

Following are some questions and answers about I-9s and the auditing process.

WHAT IS A FORM I-9?

- An I-9 is an employment eligibility verification form. All U.S. employers must complete and retain an I-9 for each individual they hire in the United States, citizens and noncitizens alike. On the form, the employer must examine the employment eligibility and identity documents an employee presents to determine if the person can work legally in the country.

WHAT DO EMPLOYERS DO WITH THE FORM?

- The forms are not filed to the government. The form I-9 must be kept by the employer either for three years after the date of hire or for one year after employment is terminated, whichever is later. The form must be available for inspection or auditing by authorized U.S. government officials.

HOW DOES THE GOVERNMENT GO ABOUT SUCH AUDITS?

- A company will receive a notice of inspection from ICE and then its I-9s will be subject to audit and review. ICE says such inspections are not done at random and are based on leads and intelligence gathering.

HOW LONG DOES THIS TAKE AND WHAT ARE THE PENALTIES?

- The whole process can take months or even years from the notice of inspection to the closing of the case, which may or may not result in a fine.

The amount of such fines has dramatically increased according to data provided by ICE. Fines totaled just over $1 million in fiscal year 2009 and rose to nearly $7 million in 2010.

(Sources: U.S. Citizenship and Immigration Services, U.S. Immigration and Customs Enforcement, Reuters)

(Compiled by Ed Stoddard, editing by Mary Milliken and Cynthia Osterman)

Immigration Law