IL HB5727

Allows municipalities with populations under 1,000,000 to have annexations subject to a "backdoor referendum" if a petition is filed by residents.

Requires petition signatures equal to at least 10% of the total votes cast for mayor or president in the last municipal election, filed within 30 days of annexation approval.

Mandates referendum be held at the next municipal election occurring at least 90 days after petition filing, with voters deciding whether annexation should proceed.

If voters reject the annexation, the municipality cannot attempt to annex that same territory for a minimum of 2 years from the original approval date.

Takes effect immediately upon becoming law.