TransCanada PipeLines Limited 2017 Annual information form March 12, 2018 Contents PRESENTATION OF INFORMATION . 2 FORWARD-LOOKING INFORMATION . 2 TRANSCANADA PIPELINES LIMITED . 4 Corporate structure . 4 Intercorporate relationships . 5 GENERAL DEVELOPMENT OF THE BUSINESS . 6 Natural Gas Pipelines . 6 Liquids Pipelines . 14 Energy . 17 BUSINESS OF TCPL . 19 Natural Gas Pipelines . 19 Liquids Pipelines . 19 Regulation of Natural Gas Pipelines and Liquids Pipelines . 19 Energy . 21 GENERAL. 21 Employees . 21 Corporate restructuring and business transformation . 21 Health, safety and environmental protection and social policies . 22 RISK FACTORS . 23 DIVIDENDS . 23 DESCRIPTION OF CAPITAL STRUCTURE. 24 Share capital . 24 DEBT . 25 CREDIT RATINGS. 25 Moody's. 25 S&P . 26 Fitch. 26 DBRS . 26 MARKET FOR SECURITIES . 27 DIRECTORS AND OFFICERS . 28 Directors . 28 Board committees . 30 Officers . 30 Conflicts of interest . 32 CORPORATE GOVERNANCE . 32 AUDIT COMMITTEE . 32 Relevant education and experience of members . 32 Pre-approval policies and procedures . 34 External auditor service fees . 34 LOANS TO DIRECTORS AND EXECUTIVE OFFICERS . 34 SECURITIES OWNED BY DIRECTORS . 35 COMPENSATION OF DIRECTORS . 35 EXECUTIVE COMPENSATION . 35 LEGAL PROCEEDINGS AND REGULATORY ACTIONS . 36 TRANSFER AGENT AND REGISTRAR . 36 MATERIAL CONTRACTS . 36 INTEREST OF EXPERTS . ..