If a Catholic wants to marry a non-Catholic, how can they assure that the marriage is recognized by the Church?

In addition to meeting the criteria for a valid Catholic marriage, the Catholic must seek permission from the local bishop to marry a non-Catholic. If the person is a non-Catholic Christian, this permission is called a "permission to enter into a mixed marriage." If the person is a non-Christian, the permission is called a "dispensation from disparity of cult." Those helping to prepare the couple for marriage can assist with the permission process.

More information is available at the USCCB web site.