Have interest earned from a savings acct, money from a remortgage. Can we split 50/50 since mortgage in both names or does 100% go on my husbands as I don't work?

I was issued the T5 as it is a joint savings account.  I understand that the person that earns the money claims the interest, but am confused if it differs if the money is from debt (mortgage) in both our names, or since I am not paying off that debt if it goes 100% on my husband's taxes.  I am a stay-at-home mom so I currently have no income.