In a May 14, 2019 Technical Interpretation (2019-0799111C6, Doiron, W), CRA confirmed that a payment to an RRSP made by a person other than the RRSP annuitant or their spouse would be treated as a premium paid (for the purposes of a deduction for RRSP contributions) by the annuitant, provided the payment was made at the direction or with the concurrence of the annuitant. The contribution receipt should be issued to the annuitant and not the third party.

ensuring the payment is made at the direction of the annuitant

If the payment was considered a gift to the RRSP, it would not be deductible but would be included in the calculation of Part X.1 Tax on excess contributions. No receipt would be issued should the payment be considered a gift.

Editors' Comment
See VTN 449(10) where CRA discussed third-party payments to a TFSA.