The following table presents the components of related party balances included in Accounts Receivable, Net and Accounts Payable on the Condensed Consolidated Balance Sheets:


(in millions)	September 30, 2026		December 31, 2025
Receivables from Related Parties
UNS Electric	$	8	$	7
UNS Gas	2		2
UNS Energy	2		—








Total Due from Related Parties	$	12	$	9

Payables to Related Parties
UNS Electric	$	2	$	1
UNS Energy	1		4





Total Due to Related Parties	$	3	$	5

The following table presents the components of related party transactions included on the Condensed Consolidated Statements of Income:


	Three Months Ended September 30,				Nine Months Ended September 30,
(in millions)	2026		2025		2026		2025
Goods and Services Provided by TEP to Affiliates
Common Costs, UNS Energy Affiliates (1)	$	7	$	7	$	21	$	19
Transmission Revenues, UNS Electric (2)	2		2		6		6
Control Area Services, UNS Electric (3)	1		1		2		2
Wholesale Revenues, UNS Electric (2)	1		1		2		2


Goods and Services Provided by Affiliates to TEP
Corporate Services, UNS Energy (4)	$	2	$	1	$	8	$	7
Purchased Power, UNS Electric (2)	1		1		2		2
Corporate Services, UNS Energy Affiliates (5)	1		—		2		1
Capacity Charges, UNS Gas (6)	—		—		1		1

(1)Common costs (information systems, facilities, etc.) are allocated on a cost-causative basis and recorded as revenue by TEP. The method of allocation is deemed reasonable by management and is reviewed by the ACC as part of the rate case process.

(2)TEP and UNS Electric sell power to each other, and TEP sells transmission services to UNS Electric. Wholesale power is sold at prevailing market prices, while transmission services are sold at FERC-approved rates through the applicable Open Access Transmission Tariff.

(4)Corporate Services, UNS Energy includes legal and audit, and Fortis' management fees. Costs for corporate services provided by UNS Energy are allocated to its subsidiaries using the Massachusetts Formula, an industry accepted method of allocating common costs to affiliated entities. TEP's allocation is approximately 84% of UNS Energy's allocated costs. TEP's share of Fortis' management fees were $2 million and $7 million for the three and nine months ended September 30, 2026, respectively, and $1 million and $6 million for the three and nine months ended September 30, 2025, respectively.

(5)Costs for corporate services (e.g., finance, accounting, tax, legal, and information technology) and other labor services for UNS Energy Affiliates are directly assigned to the benefiting entity at a fully burdened cost when possible.