The NR4 Return you file each year identifies the amount you remit to the CRA as withholding tax. But that’s for gross rent. If you want them to deduct from the net rental amount, you must file the form NR6. Calculate both the expected gross and net income for your property along with the expenses. Include it with the NR6 Form, file, and wait for CRA’s approval. Remember if you are not a resident of Canada, you must file a Section 216 Return by June 30 if you choose the latter alternative.