And also how accurate the input numbers are. Many divorced parents are distrustful of each other and give each other only vague numbers, resulting in derived inaccuracy for whoever puts them into the NPC. If both of you do not mind sharing accurate financial numbers with the kid and each other*, then you will be able to use good numbers in NPCs of colleges that want both.
*Note that although CSS Profile has the custodial and non-custodial parents fill in information separately for the actual financial aid application, NPCs do not have this provision. It is also possible for someone who knows the actual FA offer and one parent’s finances to reverse-engineer ranges of what the other parent’s finances are using the college’s NPC.