My minor son received a permanent fund dividend. His dad contributed 50% of it to a 529 plan. Is the entire $1,600 PFD taxable or just the $800 he received directly?

My son has $5,000 in income from his job and is required to file his own tax return, but his father refuses to provide the PFD 1099 form so we are at a loss as to what to do. The Permanent Fund Division refuses to help because his father is the custodial parent and they see this as a personal matter and not a taxation issue.  As a single mom I cannot afford to hire an accountant or an attorney so I need to get this right.