We have been sperated for 9 months and I am looking to relocate to another state, due to EX not helping support minor children.

You have actual custody of the children? There is no court order about custody either?

Yes, you could, but the ex can file for custody or visitation in your present state (for as much as six months after the move), and you could be required to return the children to that state.

How is moving going to make the ex support the child?

What is the current status of the relationship as far as papers that have been filed? Is there a child support order? What State is this in as local laws vary widely?

This is way to vague to answer. My first instinct is to say that if you care about your children having a meaningful relationship with their father at all, you will not move. I'm not going to go into much not knowing your situation (as others have asked... what is the status in terms of papers being filed? Custody? etc. ) but I will tell you from very close personal experience that what you're talking about has the potential to destroy lives. Think very carefully before you decide to do this to your kids. Don't do this out of bitterness or vengefulness for your ex. You guys are separated... it's not about you two anymore. And there are so many divorced parents who fail to forget that it's not about them, it's about the kids. Don't be one of them. But yes, please, elaborate on your situation before seeking advice.

It helps to even know where this is. In Australia this can be pursued as a kidnapping charge. My ex can't move interstate without my written consent, even without a court order in place since I have not neglected my right of visitation for our children, one of whom lives with me as well so it goes both ways.

It's seriously easier to get the written permission to move interstate than risk a federal charge for kidnapping. If they refuse you can definitely take it to a family law specialist who will frequently be happy to stick it to your ex in every way legally possible if they really are derelict in their responsibilities to your children.

I don't agree with children being used as pawns in personal struggles after a break up, but if you're honest with the few details given then if it forces them to be more proactive in raising the children you're better off overall, even if it does prevent you from moving as easily as you'd like. Alternatively if they blow off the situation then you have at least made an effort to obey the law and have more solid ground to make a defense later on if they decide to contest you moving on grounds of access.