CHICAGO (WLS) -- An upcoming federal deadline for Americans to get their REAL ID has created some confusion, according to Illinois Secretary of State Alexi Giannoulias.

First, what is a REAL ID? - The document is a form of identification required mainly to board flights within the United States.

However, it is not mandatory, Giannoulias clarified.

Illinoisians do not need it "for driving a vehicle or required for valid identification or proof of citizenship."

DHS will begin to enforce the Real ID requirement on May 7, 2025.

The federal identification looks almost as a driver's license but has a compliant star marking.

To accommodate, the office added more daily appointments by nearly 2,500 at the 44 appointment-only DMVs in Chicago and the suburbs.

READ MORE | Americans will need Real ID to travel, enter US federal buildings in 2025

Here are the requirements to apply for a REAL ID in Illinois:

1.A U.S. birth certificate, U.S. passport, Naturalization Certificate, Report of Birth Abroad or a Certificate of Citizenship. If you are not a U.S. citizen, an employment authorization document, a permanent resident card or a foreign passport with an approved I-94 form is also acceptable. If you've changed your name, you'll need to provide name change documents.

2.Proof of a full Social Security number (SSN). Examples include: a Social Security card, a W-2 or a pay stub with your full SSN.

3.Two current residency documents that list your full name. Examples include: a utility bill, rental agreement, deed/title or a bank statement.

4.Proof of your signature. Examples include: a signed credit or debit card, canceled check, or current state driver's license or state ID.