Canon 1124. Marriage between two baptized persons, one of whom was baptized in the
Catholic Church or received into it after baptism, and the other a member of a
Church or ecclesial community not in full communion with the Catholic Church, cannot be celebrated without the express permission of the competent authority.
[revised wording according to m.p. Omnium in mentem, 26.X.2009]

Canon 1125. The local Ordinary can grant this permission if there is a just and reasonable cause. He is not to grant it unless the following conditions are fulfilled:

1° the catholic party is to declare that he or she is prepared to remove dangers of defecting from the faith, and is to make a sincere promise to do all in his or her power in order that all the children be baptised and brought up in the catholic
Church;

2° the other party is to be informed in good time of these promises to be made by the catholic party, so that it is certain that he or she is truly aware of the promise and of the obligation of the catholic party

3° both parties are to be instructed about the purposes and essential properties of marriage, which are not to be excluded by either contractant.

Canon 1126. It is for the Episcopal Conference to prescribe the manner in which these declarations and promises, which are always required, are to be made, and to determine how they are to be established in the external forum, and how the non-catholic party is to be informed of them.

Canon 1127. §1 The prescripts of can. 1108 are to be observed for the form to be employed in a mixed marriage; if however a Catholic party contracts marriage with a non-Catholic party of an Eastern Rite, the canonical form of the celebration must be observed for liceity only; for validity, however, the presence of a priest is required notwithstanding whatever else is to be observed in accordance with the law.
[revised wording according to m.p. De concordia inter Codices, 31.V.2016]

§2 If there are grave difficulties in the way of observing the canonical form, the local
Ordinary of the catholic party has the right to dispense from it in individual cases, having however consulted the Ordinary of the place of the celebration of the marriage; for validity, however, some public form of celebration is required. It is for the Episcopal Conference to establish norms whereby this dispensation may be granted in a uniform manner.

§3 It is forbidden to have, either before or after the canonical celebration in accordance with §1, another religious celebration of the same marriage for the purpose of giving or renewing matrimonial consent. Likewise, there is not to be a religious celebration in which the catholic assistant and a non-catholic minister, each performing his own rite, ask for the consent of the parties.

Canon 1128. Local Ordinaries and other pastors of souls are to see to it that the catholic spouse and the children born of a mixed marriage are not without the spiritual help needed to fulfil their obligations; they are also to assist the spouses to foster the unity of conjugal and family life.

Canon 1129. The provisions of cann. 1127 and 1128 are to be applied also to marriages which are impeded by the impediment of disparity of worship mentioned in can.
1086 §1.