NOTICE DATE: October 15, 2026

NOTICE TYPE: M-A101526-01 Operations

SHORT DESCRIPTION: Window to submit Declarations of Weather Preparedness (DoWPs) via the ERCOT Weatherization & Inspection (W&I) Market Participant Portal (Portal) is November 1 - December 1, 2026

INTENDED AUDIENCE: Market Participant personnel involved in Public Utility Commission of Texas (PUC) Weather Emergency Preparedness Rule, 16 Texas Administrative Code (TAC) 25.55, activities for Generation Entities (GEs) and Transmission Service Providers (TSPs).

DAYS AFFECTED: Sunday, November, 1, 2026 to Tuesday, December 1, 2026

LONG DESCRIPTION: GEs and TSPs must submit DoWPs to ERCOT through the Portal between November, 1, 2026 at 00:00:00 and December 1, 2026 at 23:59:59.

ACTION REQUIRED: Each GE and TSP representative who performs any portion of the DoWP submission process in the Portal, including but not limited to: (i) preparing Appendix A, (ii) uploading the notarized attestation, or (iii) attaching associated documents, must have a Digital Certificate with the "Manager" role assigned (SN_M_W_MGR_ECEII) to access the Portal. The GE or TSP User Security Administrator (USA) must coordinate obtaining a Digital Certificate for every person needing access to the Portal.

NOTE: The USA should not assign the "Manager" and "View" roles to any single person's Digital Certificate because the permission level will default to the "View" role which does not have the necessary "write" privileges associated with the Manager role. 

ADDITIONAL INFORMATION: Refer to the Weatherization & Inspection Market Participant Portal User Guide for detailed instructions on accessing and using the Portal.

The user guide and other relevant documents are found on the Winter Weather Readiness page of ERCOT's public web page.

USAs unfamiliar with the Digital Certificate process may review the ERCOT Digital Certificate User Guide under the "Certificate Documentation" section of the Digital Certificate Security Information webpage.

Q&A sessions to respond to questions about submitting DoWPs through the Portal will take place via Webex on the following schedule:

• Monday, November 2, 2026, 9:00-10:00 a.m.
• Tuesday, November 10, 2026, 1:00-2:00 p.m.
• Wednesday, November 18, 2026, 2:00-3:00 p.m.
• Monday, November 30, 2026, 11:00 a.m.-12:00 p.m.

The Webex meeting information for each Q&A session appears on the ERCOT Calendar.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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