Well, part XIII withholding tax is technically an income tax imposed on a non-resident in respect of a payment. It's generally passive amounts. The 25% rate is the base rate, which can be reduced under tax treaties.
Yes, obviously, if you don't report and pay your taxes, that can be tax evasion. Passive payments out of Canada to non-residents do attract this part XIII withholding tax. This could be dividends, rents, royalties, payments in respect of certain tax-deferred vehicles, RRSPs, and it can be related to ALDAs that way. It's a measure that ensures the appropriate amount of tax is being paid by non-residents. The withholding mechanism on the payment of the amount helps to ensure that it's collectible when the money leaves Canada.