When Coinbase initiates a refund for a customer's Interac e-Transfer, the customer must accept the refund for it to be successful. To do this, the customer must access the authenticated link from Interac, and provide the secret answer provided by Coinbase.
Accept a Coinbase Interac refund
In your email inbox configured with Interac, check for the following two (2) emails:
Select the URL from the Interac email to complete acceptance of the refund
Login to your banking portal
Input the secret answer from the Coinbase email
Interac refund troubleshooting & details
Confirm you’re using the right Interac secret answer. After 3 wrong attempts the refund will be cancelled for security reasons by Interac
Coinbase recommends configuring autodeposit for Interac e-Transfers, which will allow you to receive refunds directly to your bank account.