Koppers Holdings Inc. — 8-K/A Filings
8 8-K/A filings on record
This page lists all 8-K/A filings submitted to the SEC by Koppers Holdings Inc. (KOP), sorted by most recent first. Each row links to the full filing on EdgarLookup. Koppers Holdings Inc. has filed 8 8-K/A documents with the SEC since 2015. To view all SEC filings by Koppers Holdings Inc., see the full filings list.
All
10-K
10-K/A
10-Q
144
144/A
3
3/A
4
4/A
424B1
424B3
5
5/A
8-A12B
8-K
8-K/A
ARS
CERTNYS
CORRESP
DEF 14A
DEFA14A
EFFECT
POS AM
POSASR
PRE 14A
S-1
S-1/A
S-3
S-3/A
S-3ASR
S-4
S-4/A
S-8
SC 13G
SC 13G/A
SCHEDULE 13G
SCHEDULE 13G/A
UPLOAD
| Form | Description | Accession Number | Filed | Period |
|---|---|---|---|---|
| 8-K/A | 8-K/A | 0001315257-26-000017 | Mar 18, 2026 | Jan 5, 2026 |
| 8-K/A | 8-K | 0001315257-25-000014 | Dec 3, 2025 | Nov 8, 2024 |
| 8-K/A | 8-K/A | 0000950170-24-052134 | May 2, 2024 | — |
| 8-K/A | 8-K/A | 0000950170-23-017934 | May 4, 2023 | — |
| 8-K/A | 8-K/A | 0001564590-18-016122 | Jun 25, 2018 | Apr 10, 2018 |
| 8-K/A | 8-K/A | 0001564590-17-015324 | Aug 3, 2017 | May 4, 2017 |
| 8-K/A | AMENDMENT NO. 1 TO FORM 8-K | 0001193125-14-389707 | Oct 30, 2014 | Aug 15, 2014 |
| 8-K/A | AMENDMENT NO. 1 TO FORM 8-K | 0001193125-11-211774 | Aug 5, 2011 | May 4, 2011 |