TRANSACTIONS WITH MAJOR CUSTOMERS AND AFFILIATES

Major Customers

Operating revenues received from three of our major customers in 2018, 2017 and 2016 are as follows (in millions):



	2018		2017		2016
Duke Energy Corporation	$	194.5	$	198.4	$	178.9
National Grid	186.1		177.4		166.3
The Southern Company, Inc.	166.2		160.0		69.6

Affiliates

We are a participant in Williams' cash management program, and we make advances to and receive advances from Williams. At December 31, 2018 and 2017, our advances to Williams totaled approximately $33.0 million and $395.2 million, respectively. These advances are represented by demand notes and are classified as Receivables - Advances to affiliate in the accompanying Consolidated Balance Sheet. Advances are stated at the historical carrying amounts. Interest income is recognized when chargeable and 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. At December 31, 2018, the interest rate was 2.24 percent.

Included in Operating Revenues in the accompanying Consolidated Statement of Comprehensive Income for 2018, 2017 and 2016 are revenues received from affiliates of $10.1 million, $10.3 million, and $11.2 million, respectively. The rates charged to provide sales and services to affiliates are the same as those that are charged to similarly-situated nonaffiliated customers.

Included in Cost of natural gas sales in the accompanying Consolidated Statement of Comprehensive Income for 2018, 2017 and 2016 is purchased gas cost from affiliates of $5.4 million, $3.9 million, and $4.3 million, respectively. All gas purchases are made at market or contract prices.

We have no employees. Services necessary to operate our business are provided to us by Williams and certain affiliates of Williams. We reimburse Williams and its affiliates for all direct and indirect expenses incurred or payments made (including salary, bonus, incentive compensation and benefits) in connection with these services. Employees of Williams also provide general, administrative and management services to us, and we are charged for certain administrative expenses incurred by Williams. These charges are either directly identifiable or allocated to our assets. Direct charges are for goods and services provided by Williams at our request. Allocated charges are based on a three-factor formula, which considers revenues; property, plant and equipment; and payroll. In management’s estimation, the allocation methodologies used are reasonable and result in a reasonable allocation to us of our costs of doing business incurred by Williams. We were billed $395.3 million, $370.4 million, and $318.4 million during 2018, 2017 and 2016, respectively, for these services. Such expenses are primarily included in Administrative and general and Operation and maintenance expenses in the accompanying Consolidated Statement of Comprehensive Income. The amount billed to us during 2016 includes $7.4 million for severance and other related costs associated with a reduction in workforce primarily recognized in the first quarter.

We provide services to certain of our affiliates. We recorded reductions in operating expenses for services provided to and reimbursed by our affiliates of $4.7 million, $3.7 million, and $4.3 million in 2018, 2017 and 2016, respectively.

We made equity distributions of $490 million, $430 million and $440 million during 2018, 2017 and 2016, respectively. In January 2019, an additional distribution of $176 million was declared and paid.

During 2018, 2017 and 2016, our parent made contributions totaling $340 million, $410 million and $502 million, respectively, to us to fund a portion of our expenditures for additions to property, plant and equipment.

During July 2017, we recorded deferred revenue and recognized a non-cash distribution to our parent of $240 million associated with funds received by WPZ related to the March 2016 WPZ agreement with the member-sponsors of Sabal Trail regarding the Hillabee Expansion and Sabal Trail projects. Although the agreement was between WPZ and the member-sponsors, since the agreement was, in part, related to furthering the completion of Hillabee, this deferred revenue is assigned to our results of operations over the 25-year term of the capacity agreement with Sabal Trail.