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Submission
Aug. 15, 2025
Submission [Line Items]  
Central Index Key 0000755001
Registrant Name UNITIL CORP
Registration File Number 333-287753
Form Type S-3
Submission Type 424B5
Fee Exhibit Type EX-FILING FEES
Offering Table N/A
Offset Table N/A N/A
Combined Prospectus Table N/A N/A