SIGNIFICANT ACCOUNTING POLICIES (Policies)

9 Months Ended

Sep. 30, 2013

SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

(a) Basis of Presentation

The Partnership uses the equity method of accounting for its investments in Great Lakes and Northern Border, over which it is able to exercise significant influence. The Partnership consolidates its investments in GTN, Bison, North Baja and Tuscarora.

On July 1, 2013, the Partnership acquired additional 45 percent membership interests in each of GTN and Bison (the 2013 Acquisition) from subsidiaries of TransCanada. The 2013 Acquisition was accounted for as a transaction between entities under common control, similar to a pooling of interests, whereby the assets and liabilities of GTN and Bison were recorded at TransCanada’s carrying value and the Partnership’s historical financial information was recast to consolidate GTN and Bison for all periods presented. Refer to Note 4 for additional disclosure regarding the 2013 Acquisition.

Use of Estimates

(b) Use of Estimates

The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Although management believes these estimates are reasonable, actual results could differ from these estimates.