Honesty is the first chapter in the book of wisdom.

Thomas Jefferson

Under Family Law in Australia you have a duty of disclosure with regards to financial matters if you participate in negotiation or go to court. Any agreement reached based on false information can be overturned.

This means you need to tell the other parent what your financial situation is. You might not like this and this might feel intrusive, but it is a requirement so that decisions are made with full knowledge. Since most financial decisions are made by agreements, stipulation or negotiated settlements, it is very important to know what you’re agreeing to, with full knowledge and information.

Exchanging information about your income, about your expenses, about what assets or property you own, and what your debts are, will influence all of these decisions. Where there is information that you don't want to share, you should talk to a lawyer or financial advisor to find out if there are any limitations.

For example you may not be required to expose the finances of a new partner depending on your circumstances, so that may be protected.

If you have a high-conflict co-parent, that is one of the things that they like to do – draw other people into the conflict, whether it's your relatives, new partners, and so on.

Don't be surprised if a high-conflict co-parent starts demanding all that information.

Generally it is not required to disclose other people’s information.

For example, in some of the most high-conflict cases I've known about, a high-conflict co-parent has wanted to add the assets of the other person’s parents saying that as the only child they would inherit so it should be part of the property pool.

A deceased estate that is in probate would be considered but not the assets of parents who are living! Family Trusts may not be exempt but in most cases a high conflict co-parent will make threats that are unfounded, so don't be caught by surprise. Always check things out with a lawyer or financial advisor.