Nstar Electric Co SEC filings NSARO
Nstar Electric Co has 405 filings in SEC EDGAR's recent list, going back to Jan 27, 1994. Its latest annual report, Form 10-K, was filed on Feb 17, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 3, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Nov 4, 2026 (results of operations, regulation fd disclosure). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 424B5 | Prospectus supplement | May 12, 2026 | — |
| FWP | Free writing prospectus | May 11, 2026 | — |
| FWP | Free writing prospectus | May 11, 2026 | — |
| 424B3 | Prospectus | May 11, 2026 | — |
| 424B5 | Prospectus supplement | Oct 16, 2025 | — |
| FWP | Free writing prospectus | Oct 15, 2025 | — |
| 424B3 | Prospectus | Oct 15, 2025 | — |
| S-3ASR | Automatic shelf registration | Apr 3, 2025 | — |
| 424B5 | Prospectus supplement | Feb 25, 2025 | — |
| FWP | Free writing prospectus | Feb 24, 2025 | — |
| FWP | Free writing prospectus | Feb 24, 2025 | — |
| 424B3 | Prospectus | Feb 24, 2025 | — |
| 424B5 | Prospectus supplement | May 21, 2024 | — |
| FWP | Free writing prospectus | May 20, 2024 | — |
| 424B3 | Prospectus | May 20, 2024 | — |
| 424B5 | Prospectus supplement | Sep 19, 2023 | — |
| FWP | Free writing prospectus | Sep 18, 2023 | — |
| 424B3 | Prospectus | Sep 18, 2023 | — |
| 424B5 | Prospectus supplement | Sep 13, 2022 | — |
| FWP | Free writing prospectus | Sep 12, 2022 | — |
| 424B3 | Prospectus | Sep 12, 2022 | — |
| 424B5 | Prospectus supplement | May 16, 2022 | — |
| FWP | Free writing prospectus | May 12, 2022 | — |
| 424B3 | Prospectus | May 12, 2022 | — |
| S-3ASR | Automatic shelf registration | Apr 13, 2022 | — |
| 424B5 | Prospectus supplement | Aug 11, 2021 | — |
| FWP | Free writing prospectus | Aug 10, 2021 | — |
| 424B3 | Prospectus | Aug 10, 2021 | — |
| 424B5 | Prospectus supplement | May 25, 2021 | — |
| FWP | Free writing prospectus | May 24, 2021 | — |
| 424B3 | Prospectus | May 24, 2021 | — |
| 424B5 | Prospectus supplement | Mar 24, 2020 | — |
| FWP | Free writing prospectus | Mar 23, 2020 | — |
| 424B3 | Prospectus | Mar 23, 2020 | — |
| 424B5 | Prospectus supplement | May 15, 2019 | — |
| FWP | Free writing prospectus | May 14, 2019 | — |
| 424B3 | Prospectus | May 14, 2019 | — |
| S-3ASR | Automatic shelf registration | Apr 30, 2019 | — |
| 424B5 | Prospectus supplement | Oct 3, 2017 | — |
| FWP | Free writing prospectus | Oct 2, 2017 | — |
| 424B3 | Prospectus | Oct 2, 2017 | — |
| 424B5 | Prospectus supplement | May 11, 2017 | — |
| FWP | Free writing prospectus | May 10, 2017 | — |
| 424B3 | Prospectus | May 10, 2017 | — |
| 424B5 | Prospectus supplement | May 24, 2016 | — |
| FWP | Free writing prospectus | May 23, 2016 | — |
| 424B3 | Prospectus | May 23, 2016 | — |
| S-3ASR | Automatic shelf registration | May 2, 2016 | — |
| 424B5 | Prospectus supplement | Nov 16, 2015 | — |
| FWP | Free writing prospectus | Nov 13, 2015 | — |
| 424B3 | Prospectus | Nov 13, 2015 | — |
| 424B3 | Prospectus | May 13, 2015 | — |
| 424B5 | Prospectus supplement | Mar 5, 2014 | — |
| FWP | Free writing prospectus | Mar 4, 2014 | — |
| 424B3 | Prospectus | Mar 4, 2014 | — |
| 424B5 | Prospectus supplement | May 15, 2013 | — |
| FWP | Free writing prospectus | May 14, 2013 | — |
| 424B3 | Prospectus | May 14, 2013 | — |
| S-3ASR | Automatic shelf registration | May 3, 2013 | — |
| 424B5 | Prospectus supplement | Oct 10, 2012 | — |
| FWP | Free writing prospectus | Oct 9, 2012 | — |
| 424B3 | Prospectus | Oct 9, 2012 | — |
| POS AM | Post effective amendment no.1 to form s-3 | Apr 10, 2012 | — |
| 424B5 | Prospectus supplement | Mar 12, 2010 | — |
| FWP | Free writing prospectus | Mar 11, 2010 | — |
| 424B5 | Prospectus supplement | Mar 11, 2010 | — |
| S-3ASR | Automatic shelf registration | Oct 9, 2009 | — |
| 424B5 | Prospectus supplement | Feb 11, 2009 | — |
| 424B5 | Prospectus supplement | Feb 10, 2009 | — |
| FWP | Free writing prospectus | Feb 10, 2009 | — |
| 424B5 | Prospectus supplement | Nov 15, 2007 | — |
| FWP | Free writing prospectus | Nov 14, 2007 | — |
| 424B5 | Prospectus supplement | Nov 14, 2007 | — |
| S-3 | Shelf registration | May 18, 2007 | — |
| 424B5 | Prospectus supplement | Mar 14, 2006 | — |
| FWP | Free writing prospectus | Mar 13, 2006 | — |
| 424B5 | Prospectus supplement | Mar 13, 2006 | — |
| 424B5 | Prospectus supplement | Apr 14, 2004 | — |
| S-3 | Shelf registration | Dec 23, 2003 | — |
| 424B5 | Prospectus supplement | Oct 11, 2002 | — |
| 424B5 | Prospectus supplement | Oct 10, 2002 | — |
| S-3 | Shelf registration | Feb 20, 2001 | — |
| S-8 POS | Post-effective amendment no. 1 to form s-8 | Nov 18, 1999 | — |
| S-8 POS | Amendment 1 to form s-8 | Jul 1, 1998 | — |
| S-8 | Employee stock plan registration | Jul 9, 1997 | — |
| 424B2 | Prospectus | Sep 27, 1995 | — |
| 424B2 | Prospectus | Jun 8, 1995 | — |
| S-3D | Boston edison company | May 31, 1995 | — |
| 424B5 | Prospectus supplement | May 11, 1995 | — |
| S-8 | Employee stock plan registration | Apr 6, 1995 | — |
| 424B3 | Prospectus | Jun 16, 1994 | — |
| S-8 | Employee stock plan registration | Jan 27, 1994 | — |
Showing 92 filings. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
New to this? Read What Are SEC Filings? 10-K, 10-Q, 8-K and Other Forms Explained.
Company profile
- Industry
- Electric Services (SIC 4911)
- Listed as
- NSARO (OTC), NSARP (OTC)
- Fiscal year ends
- December 31
- Incorporated in
- MA
- Headquarters
- Boston, MA
- SEC CIK
- 13372
- Former names
- BOSTON EDISON CO (until Jan 5, 2007)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.