Paragraph 16 I1

Network Rail must, on receipt of a request from the relevant undertaker, from time to time provide the relevant undertaker free of charge with written estimates of the costs, charges, expenses and other liabilities for which the relevant undertaker is or will become liable under this Part (including the amount of the relevant costs mentioned in paragraph 15) and with such information as may reasonably enable the relevant undertaker to assess the reasonableness of any such estimate or claim made or to be made pursuant to this Part (including any claim relating to the relevant costs).