DEBT AND CREDIT FACILITIES (Tables)

9 Months Ended

Sep. 30, 2020

Debt Disclosure [Abstract]

Schedule of debt and credit facilities

(unaudited) (millions of dollars)	September 30, 2020	Weighted Average Interest Rate for the Nine Months Ended September 30, 2020		December 31, 2019	Weighted Average Interest Rate for the Year Ended  December 31, 2019
TC PipeLines, LP
Senior Credit Facility due 2021	—	—		—	—
2013 Term Loan Facility due 2022	450	2.03%		450	3.52%
4.65% Unsecured Senior Notes due 2021	350	4.65%	(a)	350	4.65%	(a)
4.375% Unsecured Senior Notes due 2025	350	4.375%	(a)	350	4.375%	(a)
3.90% Unsecured Senior Notes due 2027	500	3.90%	(a)	500	3.90%	(a)
GTN
3.12% Series A Senior Notes due 2030	175	3.12%	(a)	—	—
5.29% Unsecured Senior Notes due 2020	—	—	(a)	100	5.29%	(a)
5.69% Unsecured Senior Notes due 2035	150	5.69%	(a)	150	5.69%	(a)
PNGTS
Revolving Credit Facility due 2023	99	2.02%		39	3.47%
Tuscarora
Unsecured Term Loan due 2021	23	2.13%		23	3.39%
North Baja
Unsecured Term Loan due 2021	50	1.85%		50	3.34%
	2,147			2,012
Less: unamortized debt issuance costs and debt discount	7			9
Less: current portion (b)	373			123
	1,767			1,880

(a)    Fixed interest rate

(b)    At September 30, 2020, this amount included TC PipeLines, LP's $350 million 4.65% Unsecured Senior Notes due in June 2021 and Tuscarora's $23 million Unsecured Term Loan due in August 2021. At December 31, 2019, this amount included GTN's $100 million 5.29% Unsecured Senior Notes due in June 2020 and Tuscarora's $23 million Unsecured Term Loan due in August 2020.

Schedule of principal repayments required on debt

The principal repayments required of the Partnership on its debt are as follows:

(unaudited)
(millions of dollars)	Principal Payments
2020	—
2021	423
2022	450
2023	99
2024	—
Thereafter	1,175
	2,147