10 ILCS 5/18-9.1

Except as otherwise provided in this Code, write-in votes shall be counted only for persons who have filed notarized declarations of intent to be write-in candidates with the proper election authority or authorities not later than 61 days prior to the election. However, whenever an objection to a candidate's nominating papers or petitions is sustained under Section 10-10 after the 61st day before the election, then write-in votes shall be counted for that candidate if he or she has filed a notarized declaration of intent to be a write-in candidate for that office with the proper election authority or authorities not later than 7 days prior to the election.

Forms for the declaration of intent to be a write-in candidate shall be supplied by the election authorities. Such declaration shall specify the office for which the person seeks election as a write-in candidate.

The election authority or authorities shall deliver a list of all persons who have filed such declarations to the election judges in the appropriate precincts prior to the election.

A candidate for whom a nomination paper has been filed as a partisan candidate at a primary election, and who is defeated for his or her nomination at the primary election, is ineligible to file a declaration of intent to be a write-in candidate for election in that general or consolidated election.

A candidate seeking election to an office for which candidates of political parties are nominated by caucus who is a participant in the caucus and who is defeated for his or her nomination at such caucus is ineligible to file a declaration of intent to be a write-in candidate for election in that general or consolidated election.

A candidate seeking election to an office for which candidates are nominated at a primary election on a nonpartisan basis and who is defeated for his or her nomination at the primary election is ineligible to file a declaration of intent to be a write-in candidate for election in that general or consolidated election.

Nothing in this Section shall be construed to apply to votes cast under the provisions of subsection (b) of Section 16-5.01.