CRA indicates that consent given over the phone or by pressing options on a touchtone phone does not constitute “express consent” to electronic information slips
For some of the information slips, most notably, the T4, T4A and T5, the issuer has the right pursuant to Reg. 209(5) to issue them in electronic format. For the others, it can only do so if (per Reg. 209(3)) it receives the ”express consent” of the recipient taxpayer, which is defined in Reg. 209(4) as consent “given in writing or in an electronic format”.
CRA indicated that consent of the taxpayer given over the phone would not be in writing or in electronic format and that an audio recording of verbal consent provided over the phone would not be so considered, as the recording would not be in an electronically readable form.
Furthermore, consent provided by selecting the electronic receipt of documents using a touch-tone phone would not so qualify, since the "act of selecting an option using a touch-tone phone does not provide clear and explicit consent in writing" and, furthermore, unless the consent provided in this scenario could be retained in an electronically readable format, it would not constitute consent in an electronic format.
Neal Armstrong. Summary of 6 November 2023 External T.I. 2022-0954001E5 under Reg. 209(4).