The Code of Canon Law defines a parish as a “certain community of the Christian faithful stably constituted in a [diocese], whose pastoral care is entrusted to a pastor… under the authority of the diocesan bishop” (canon 515 § 1). Moreover, a parish ordinarily “is to be territorial, that is, one which includes all the Christian faithful of a certain territory” (canon 518). Therefore, each parish ordinarily has a defined set of boundaries.
The pastor must know the boundaries of his parish so that he can fulfill his obligation “to make provision so that the word of God is proclaimed in its entirety to those living in the parish” (canon 528 § 1). “He is to make every effort, even with the collaboration of the Christian faithful, so that the message of the gospel comes also to those who have ceased the practice of their religion or do not profess the true faith” (same canon).
Though Catholics should ordinarily attend the parish in which they live, they remain free to attend the parish of their choice. Since this practice has become very common in the United States, most parishes today encourages their faithful to register. Parish registration is not foreseen in the Code of Canon Law, but it is a practical administrative tool that responds to an organizational need. It in no way diminishes the pastor’s responsibility to proclaim Christ to all in the parish’s boundaries – registered or not, Catholic or not.
Due to the closure of various parishes in the Birmingham area over the past couple of decades, as well as the opening of new ones, parish boundaries are under study and revision at this time.