Year ended December 31, 2019

2. Basis of preparation (continued):

(e) Use of estimates and judgements (continued):

Estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the year in which the estimates are revised and in any future periods affected.

In particular, significant areas where upon estimation was required that have the most significant effect on the amounts recognized in these consolidated financial statements, include:

(i) Note 3(j) – Deferred revenue: determination of the performance obligation for contributions from customers and the related amortization period;(ii) Note 5 – Trade accounts receivables: allowance for impairment. Unbilled revenue: measurement of revenues not yet billed;(iii) Note 7 – Property, plant and equipment: useful lives and the identification of significant components of property, plant and equipment;(iv) Note 14 – Employee future benefits: measurement of the defined benefit obligation;(v) Note 24 – Financial instruments and risk management: valuation of financial instruments.

Information about critical judgements in applying accounting policies that have the most significant effect on the amounts recognized in the consolidated financial statements, include:

(i) The Corporation’s determination that they are acting as a principal for electricity distribution and therefore have presented the electricity revenues on a gross basis.

(f) Rate regulation:

EWU is regulated by the OEB, under the authority granted by the Ontario Energy Board Act, 1998. Among other things, the OEB has the power and responsibility to approve or set rates for the transmission and distribution of electricity, providing continued rate protection for electricity customers in Ontario, and ensuring that transmission and distribution companies fulfill obligations to connect and service customers. The OEB may also prescribe license requirements and conditions of service to local distribution companies (“LDC”), such as EWU, which may include, among other things, record keeping, regulatory accounting principles, separation of accounts for distinct businesses, and filing and process requirements for rate setting purposes.