Where an imported supply was self-assessed for Division IV tax, CRA can assess to reverse this tax if it has assessed the non-resident for not charging Division II tax
Where a Canadian financial institution self-assessed itself for Division IV GST on an imported supply from an unregistered non-resident and then CRA assesses the non-resident for failure to have registered and to have collected and remitted GST on that supply:
the financial institution would be able to request to have its return reassessed in order to have the amount that was originally included as Division IV tax removed and refunded to the financial institution subject to the applicable legislative time limit.
This is a better approach to getting a recovery of the tax which the non-resident would now be seeking to collect from it than to apply to CRA for a rebate, as there is a two-year time limitation on rebate claims, and they are not available if the return is question has been assessed for some other reason.
Neal Armstrong. Summary of 23 March 2017 CBA Commodity Taxes Roundtable, Q.17 under ETA s. 261(1) and s. 296(6).