How to void a pre-nuptial agreement?

You can only void--or otherwise cancel--an agreement like this in the following ways:

1) By mutual agreement; if the two of you want to cancel it, you can.

2) If you can show that there was fraud on the part of your husband in terms of either inducing your to sign the agreement or in representing the contents and effect of the agreement. However, that is unlikely unless you can show that he knowingly lied about the agreement--but you write that you, not him, were the driving force behind it.

3) You can show that either you or your husband lacked legal capacity (e.g. mentally ill, underage) at the time the agreement was executed.

4) You can show that the agreement as written does not actually reflect the intentions of or agreement between the two of you--basically, that there is some significant error in the agreement that you and your husband did not have the chance to catch in the signing. If so, a court will probably not  strike down the agreement entirely, but may rewrite it to reflect the correct understanding.

5) If the marriage itself is voided (e.g. annulled, not divorce) due to some significant problem with it, like lies about wanting to have children, underage, mentally infirm at the time of marriage, was still in a prior marriage at the time, etc.