Regarding his address, usually, it's where you reside on December 31st of the tax year. Since he moved in August and returned in January, he'd likely use his Edmonton address. As for dorm costs, they can be deductible if he meets certain criteria, like being enrolled full-time. When my cousin attended private schools like Oxford Academy, she found out her dorm expenses were deductible. It made a real difference for her during tax time!