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IRS-authorized e-file provider · not the IRS

Nonprofit · EIN 36-3946273

THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT

Also known as ILLINOIS CHAPTER

Tax-exempt · BUFFALO GROVE, IL 60089

Address and contacts

Address (IRS master file)
1130 WEST LAKE COOK ROAD, BUFFALO GROVE, IL 60089-1986
In care of
% MARK HUTTON
Mailing address (990-N for 2025)
1130 West Lake Cook Road, Buffalo Grove IL 60089
Principal officer (990-N for 2025)
Brian Bilderback, 1130 West Lake Cook Road, Buffalo Grove IL 60089

What it must file and when

IRS records say it files Form 990-N (e-Postcard). Gross receipts normally $50,000 or less. Its accounting year ends in December, so each return is due on the 15th day of the 5th month after that.

Tax yearYear endedDueIRS public records
2025December 31, 2025May 15, 2026990-N on file
2024December 31, 2024May 15, 2025990-N on file
2023December 31, 2023May 15, 2024990-N on file

File the 2026 990-N for THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT

Due May 17, 2027 · e-filed with the IRS by 990.tax, an IRS-authorized e-file provider

IRS record

EIN
36-3946273
Tax-exempt status
501(c)(6): Business league or chamber of commerce
Donations deductible
No
Exempt since
1994
Accounting year ends
December
Files
Form 990-N (e-Postcard)

Filing history

FormYear endedRevenueExpensesAssetsReturn
990-N for 2025
Officer: Brian Bilderback
December 31, 2025≤ $50,000 receipts––e-Postcard
990-N for 2024
Officer: Brian Bilderback
December 31, 2024≤ $50,000 receipts––e-Postcard
990-N for 2023
Officer: Brian Bilderback
December 31, 2023≤ $50,000 receipts––e-Postcard
990-N for 2022
Officer: Heather Horvath
December 31, 2022≤ $50,000 receipts––e-Postcard
990-N for 2021
Officer: Heather Horvath
December 31, 2021≤ $50,000 receipts––e-Postcard
990-N for 2020
Officer: Heather Horvath
December 31, 2020≤ $50,000 receipts––e-Postcard
990-N for 2019
Officer: Heather Horvath
December 31, 2019≤ $50,000 receipts––e-Postcard

990-N: the IRS bulk file holds only the latest e-Postcard per organization; earlier years come from archived copies of that file since 2020 and can have gaps (the IRS e-Postcard search lists every one). 990, 990-EZ, 990-PF, 990-T: every e-filed return in the IRS e-file index since 2019; XML for the latest three processing years, amounts from the IRS Statistics of Income extracts before that. PDF copies and determination letters at the IRS (search EIN 36-3946273).

Questions about THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT

What is the EIN of THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT?
The employer identification number (EIN) of THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT is 36-3946273.
Is THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT tax-exempt?
Yes. The IRS lists it as tax-exempt under section 501(c)(6) since 1994.
Are donations to THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT tax-deductible?
No. The IRS master file says contributions to it are not deductible.
Which annual return does THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT file?
Form 990-N (e-Postcard). Gross receipts normally $50,000 or less.
When is the next return of THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT due?
The return for tax year 2026 (the year ending December 31, 2026) is due May 17, 2027. Form 8868 extends it by six months; the 990-N cannot be extended.
When did THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT last file with the IRS?
The latest return in the IRS public files is the 990-N for 2025 for the year ended December 31, 2025.
Who is the principal officer of THE INTERNATIONAL ASSOCIATION OF SPECIAL INVESTIGATION UNIT?
The 990-N for 2025 names Brian Bilderback.

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