Can I use 000-000-000 as a SIN# for a non-resident spouse? Is it legally allowed by CRA?

Yes, if your spouse does not have a Social Insurance Number, you should enter 000 000 000 in that field.

Thanks! I was just confused if it's legally permissible from CRA 🙂

Yes, it is legal to enter 000 000 000 in the Social Insurance Number field if your spouse does not have one as a non-resident.