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Tax Returns/Forms

File and Pay Online

Save Time and File Online!  

To file your sales and use tax return online visit the following website:

​​​www.salestaxonline.com 


*Note: The City accepts payment by both ACH Debit and ACH Credit if you file online.

If you have any questions, please contact the Sales Tax Division at 303-538-7400.


2024 Quarterly Bag Fee Returns now available under "Forms." Please complete and mail within 20 days following each calendar quarter to:

 9500 CIVIC CENTER DRIVE THORNTON, CO 80229.