X0306 4 2018-05-15 0 0001075607 TC PIPELINES LP TCP 0001208353 Stark Jack 700 LOUISIANA STREET HOUSTON TX 77002-2700 1 0 0 0 Deferred Share Units 2018-05-15 4 A 0 538 25.72 A Common units representing limited partner interest 538 21836 D Upon termination of service as a director, Deferred Share Units ("DSUs") recorded in the reporting person's account will be settled, at the reporting person's election, in common units representing a limited partner interest in TC PipeLines, LP ("Common Units") at no additional cost on a 1 for 1 basis or in cash of equivalent value, less applicable withholdings. The DSUs are immediately fully vested and are redeemable only following Mr. Stark's termination of Board service. The DSUs were credited to the director's share unit account as distributions, effective on the payment date for distributions paid by TC PipeLines, LP on the Common Units. Pursuant to the Deferred Share Unit Plan for Non-Employee Directors (2013), the number of DSUs credited for distributions is calculated based on the distribution declared and paid on Common Units multiplied by the number of DSUs in the director's share account on the record date of such distribution, divided by the fair market value Common Units on the payment date for such distribution. /s/ Jon A. Dobson, Attorney-in-Fact for Jack Stark 2018-05-16