# EDGAR Filing Document

**Accession Number:** 0001315257
**File Stem:** 0001315257-26-000027
**Filing Date:** 2026-3
**Character Count:** 1249
**Document Hash:** da5de85eea465f0002edd1c90ef9afbc
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001315257-26-000027.hdr.sgml**: 20260327

**ACCESSION NUMBER**: 0001315257-26-000027

**CONFORMED SUBMISSION TYPE**: ARS

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260327

**DATE AS OF CHANGE**: 20260327

**EFFECTIVENESS DATE**: 20260327

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Koppers Holdings Inc.
- **CENTRAL INDEX KEY:** 0001315257
- **STANDARD INDUSTRIAL CLASSIFICATION:** LUMBER & WOOD PRODUCTS (NO FURNITURE) [2400]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 201878963
- **STATE OF INCORPORATION:** PA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** ARS
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-32737
- **FILM NUMBER:** 26807970

**BUSINESS ADDRESS:**
- **STREET 1:** 436 SEVENTH AVENUE
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15219
- **BUSINESS PHONE:** 412-227-2001

**MAIL ADDRESS:**
- **STREET 1:** 436 SEVENTH AVENUE
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15219

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** KI Holdings Inc.
- **DATE OF NAME CHANGE:** 20050124

### Attached PDF Documents

**Attachment 1:** `a2025arscombined_31826prin.pdf`

_No text found in this document._