4800 West 92nd Avenue Westminster, CO 80031

Detailed Filing Information

Returns are due on or before the 20th day of the month following the end of a reporting period. If the due date falls on a Saturday, Sunday, or legal holiday, the due date is extended to the next business day (see below). List the reporting period and due date on all returns. Mailed returns must be postmarked by the due date and mailed to:

City of Westminster
Sales Tax Division
P.O. Box 17107
Denver, CO 80217-7107

Please do not staple checks or other attachments to the return. This address is for Westminster tax payments only. Other payments to the city should not be sent to this address.

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Tax Return Instructions

Sales & Use Tax Return Instructions
Accommodations Tax Return Instructions
Admissions Tax Return Instructions

Blank returns are available on the Forms page.

Learn how to File Online

Learn how to F.A.S.T. File and pay taxes due
Learn how to F.A.S.T. File a zero return

Is your return complete?

In order to be "on time", all taxes due must be correctly reported and paid by the due date. Avoid penalties and interest by checking for the following.

  • The return shows the applicable reporting period covered.
  • The return shows the correct due date (see below).
  • The return shows your 7-digit Westminster tax account number.
  • The return shows your legal name.
  • The return shows your current mailing address. Complete Schedule A if this information has changed since your last filing.
  • All required lines have been completed even if the amount shown is $0.00.
  • The return is signed.

Standard Due Dates

Period Covered

Due Dates

Due Dates

Due Dates

Monthly Filing      
















































Quarterly Filing      
January - March




April - June




July - September




October - December




Annual Filing      
January - December