In the case of a joint account, who should show "interest income". I am
filing as resident alien. My husband's filing as non resident alien (and does
not have to pay taxes on interest income, I believe).
Whoever's social security is on 1099-INT. If the interest is from a US bank and 1099-INT has his social or other ID number, your husband needs to pay taxes on that interest.
I think you are incorrect. If the husband (who is a non-resident alien) files Form 1040NR and the 1099-INT has his SSN/ITIN on the account, then the interest is NOT taxable.
If the Form 1099-INT has her SSN/ITIN on it OR they are filing jointly and both will be treated as resident aliens, then the interest is taxable.