If I want a Priest whom is my Spiritual Director to concelebrate a sacrament at my parish, does he need permission from the parish priest. In other words, does he have to submit a formal letter requesting permission to concelebrate. He was previously, Parochial Vicar at my parish.
Can. 902 Unless the welfare of the Christian faithful requires or suggests otherwise, priests can concelebrate the Eucharist…
Can. 903 A priest is to be permitted to celebrate even if the rector of the church does not know him, provided that either he presents a letter of introduction from his ordinary or superior, issued at least within the year, or it can be judged prudently that he is not impeded from celebrating.
He only needs to issue a formal letter of request if he is completely unknown to the pastor or from so far away that it would not be easy to reasonably check his status. Otherwise a simple telephone call ahead of time will do.