Can spouse claim all rental income on second property?
As the property title is in both names, the income/expenses/capital gain are to be split 50/50. If she did all the work,she should be paid a salary. If she put down the downpayment, you owe her your share. Your intention to shift all income and capital gain to her is presumably she has less income than you. You both could have thought of this tax planning when you bought the property, and registered the property in her name only at that time.
