The exemption in s. 212(1)(b)(ii)(C) is not applicable to refund interest.
General discussion of s. 212(1)(b)(ii)(C) exemption for governmental obligations.
An amount paid by a guarantor in respect of interest payable under a guaranteed obligation is subject to the withholding tax unless the obligation is one on which the interest is exempt under one of the exemptions in s. 212(1)(b).