v3.25.4
DEBT AND CREDIT AGREEMENTS (Tables)
 12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Summary of Credit Facilities
As at December 31, 2025, Hydro One’s consolidated committed, unsecured, and revolving credit facilities (Operating Credit Facilities) consisted of the following:
(millions of dollars)MaturityTotal
Amount		Amount
Drawn
Hydro One Inc.
    Revolving standby credit facilities1,2
June 20303,050 — 
Hydro One
    Five-year senior, revolving term credit facility2
June 2030250 — 
Total3,300 — 
1 On June 1, 2024, Hydro One Inc. increased the committed amount under the Operating Credit Facilities by $750 million.
2 On June 1, 2025, the maturity dates for the Operating Credit Facilities were extended from June 2029 to June 2030.
Summary of Outstanding Long-Term Debt
The following table presents long-term debt outstanding as at December 31, 2025 and 2024:
As at December 31 (millions of dollars)
20252024
1.76% Series 45 notes due 2025
— 400 
2.97% Series 40 notes due 2025
— 350 
5.54% Series 57 notes due 20251
— 400 
2.77% Series 35 notes due 2026
500 500 
Floating-rate Series 56 notes due 20262
425 425 
4.91% Series 52 notes due 2028
750 750 
3.02% Series 43 notes due 2029
550 550 
3.93% Series 53 notes due 2029
550 550 
2.16% Series 46 notes due 2030
400 400 
7.35% Debentures due 2030
400 400 
1.69% Series 49 notes due 2031
400 400 
2.23% Series 50 notes due 2031
450 450 
6.93% Series 2 notes due 2032
500 500 
3.94% Series 61 notes due 2032
450 — 
4.16% Series 54 notes due 2033
450 450 
3.90% Series 64 notes due 2033
1,200 — 
6.35% Series 4 notes due 2034
385 385 
4.39% Series 59 notes due 2034
550 550 
4.25% Series 60 notes due 2035
1,075 1,075 
4.30% Series 62 notes due 2035
300 — 
5.36% Series 9 notes due 2036
600 600 
4.89% Series 12 notes due 2037
400 400 
6.03% Series 17 notes due 2039
300 300 
5.49% Series 18 notes due 2040
500 500 
4.39% Series 23 notes due 2041
300 300 
6.59% Series 5 notes due 2043
315 315 
4.59% Series 29 notes due 2043
435 435 
4.17% Series 32 notes due 2044
350 350 
5.00% Series 11 notes due 2046
325 325 
3.91% Series 36 notes due 2046
350 350 
3.72% Series 38 notes due 2047
450 450 
3.63% Series 41 notes due 2049
750 750 
2.71% Series 47 notes due 2050
500 500 
3.64% Series 44 notes due 2050
250 250 
3.10% Series 51 notes due 2051
450 450 
4.00% Series 24 notes due 2051
225 225 
4.46% Series 55 notes due 2053
675 675 
4.85% Series 58 notes due 2054
1,000 1,000 
4.95% Series 63 notes due 2055
350 — 
4.80% Series 65 notes due 2056
400 — 
3.79% Series 26 notes due 2062
310 310 
4.29% Series 30 notes due 2064
50 50 
Hydro One Inc. long-term debt (a)18,620 17,070 
1.41% Series 2020-1 notes due 2027
425 425 
Hydro One long-term debt (b)425 425 
19,045 17,495 
Add: Net unamortized debt premiums39 41 
Add: Realized mark-to-market gain1
— 3 
Less: Unamortized deferred debt issuance costs(67)(60)
Total long-term debt19,017 17,479 
1 In October 2023, Hydro One Inc. entered into a $400 million fixed-to-floating interest-rate swap agreement to convert the $400 million Medium Term Note (MTN) Series 57 notes matured October 20, 2025, into a variable rate debt. This swap was accounted for as a fair value hedge. In December 2023, this swap was terminated with a payment received of $6 million on settlement, which had been amortized over the term of the related note.
2 The interest rates of the floating-rate notes are referenced to the daily compounded Canadian overnight repo rate average, plus a margin.
(a) Hydro One Inc. long-term debt
As at December 31, 2025, long-term debt of $18,620 million (2024 - $17,070 million) was outstanding, the majority of which was issued under Hydro One Inc.’s MTN Program. In February 2024, Hydro One Inc. filed a short form base shelf prospectus in connection with its MTN Program, which expires in March 2026.
In 2025, Hydro One Inc. issued long-term debt totalling $2,700 million (2024 - $2,750 million) and repaid long-term debt of $1,150 million (2024 - $700 million) under the MTN Program.
(b) Hydro One long-term debt
As at December 31, 2025, long-term debt of $425 million (2024 - $425 million) was outstanding. On August 19, 2024, Hydro One filed a short form base shelf prospectus (Universal Base Shelf Prospectus) with securities regulatory authorities in Canada. The Universal Base Shelf Prospectus allows Hydro One to offer, from time to time in one or more public offerings, debt, equity or other securities, or any combination thereof, during the 25-month period ending in September 2026. As at December 31, 2025, no securities have been issued under the Universal Base Shelf Prospectus. During the years ended December 31, 2025 and 2024, no long-term debt was issued or repaid.
Summary of Long-Term Debt
The total long-term debt is presented on the consolidated balance sheets as follows:
As at December 31 (millions of dollars)
20252024
Current liabilities:
    Long-term debt payable within one year925 1,150 
Long-term liabilities:
    Long-term debt18,092 16,329 
Total long-term debt19,017 17,479 
Summary of Principal Repayments and Related Weighted Average Interest Rates
As at December 31, 2025, future principal repayments, interest payments, and related weighted-average interest rates were as follows:
Long-Term Debt
Principal Repayments		Interest
Payments		Weighted-Average
Interest Rate
(millions of dollars)(millions of dollars)(%)
Year 1925 792 2.8 
Year 2425 775 1.4 
Year 3750 751 4.9 
Year 41,100 724 3.5 
Year 5800 675 4.8 
4,000 3,717 3.6 
Years 6-105,760 2,800 4.2 
Thereafter9,285 4,927 4.5 
19,045 11,444 4.2