Do I pay land transfer tax if I add someone to my property title in Ontario?

Adding another person to the title of your Ontario property is a transfer of an interest in land and can attract land transfer tax. The LTT is calculated on the value of the consideration that the incoming co-owner provides — which includes any amount they pay, plus any share of the existing mortgage they are assuming.

If you add someone to title for free with no mortgage on the property (a gift of a partial interest), the consideration is nominal or nil. In that case, LTT may be minimal or zero — but the Ministry of Finance may look at the fair market value of the interest transferred if the circumstances suggest value was exchanged.

If there is a mortgage on the property, the incoming co-owner's share of the outstanding mortgage balance is generally treated as consideration they are assuming, which triggers LTT. Adding a spouse, child, or other family member to title while a mortgage exists therefore commonly attracts LTT even if no cash is paid. Have a real estate lawyer calculate the LTT exposure before making any title change.