Williams Companies WMB Related Party Transaction, Rate

Transco and NWP are participants in Williams’ cash management program, and thus make advances to and receive advances from Williams. At March 31, 2025 and December 31, 2024, Transco’s advances to Williams totaled approximately $567 million and $638 million, respectively. These advances are represented by demand notes and are classified as Trade accounts and other receivables - Advances to affiliate in the Balance Sheet. Advances to Williams from NWP totaled approximately $62 million at March 31, 2025. These advances are represented by demand notes and are classified as Trade accounts and other receivables - Advances to affiliate in the Balance Sheet. NWP’s advances from Williams totaled approximately $26 million at December 31, 2024. These advances from Williams are classified as Payables - Advances from affiliate. Advances are stated at the historical carrying amounts. Interest expense and income are recognized when earned and the collectability is reasonably assured. The interest rate on these intercompany demand notes is based upon the daily overnight investment rate paid on Williams’ excess cash at the end of each month, which was approximately 4 percent at March 31, 2025. The net interest income from these advances was $6 million and $16 million for the three months ended March 31, 2025 and March 31, 2024, for Transco respectively, and $2 million for the three months ended March 31, 2024 for NWP. The net interest income from these advances for NWP was immaterial for the three months ended March 31, 2025. Such interest income is included in Interest income in the Statement of Net Income for Transco and Other income (expense) – net in the Statement of Net Income for NWP.