The predetermined withholding tax amount may vary depending whether the Profit is considered capital gains or business income.  If the profit is considered capital gains, the withholding tax is 25% of the profit; If the profit is considered business income, the withholding tax is based on the various marginal Canadian tax rates applicable based on the amount of the profit - this determination is based on each individual case. 

Please note that at the Clearance Certificate tax level, selling commission and professional fees are not "deductible" when computing the profit amount.  Since it takes at least ten weeks for CRA to process and to issue the clearance Certificate, it is recommended that the preparation/compilation of the documents required for submission to CRA is started early.

Subsequent to December 31 of the year of the sale, the non-resident Vendor will file an additional and separate Section 115 Income Tax Return Reporting the gain on the sale less any commissions and professional Fees paid as a result of the sale.  Therefore, in virtually every set of Circumstances, the non-resident taxpayer will have a refund available to them.  This refund is generally the incentive CRA leaves on the table to ensure that the non-resident taxpayer does in fact file the final income tax return reporting the sale. (Note however that this filing is not mandatory since the filing of the Canadian tax return is optional.)