Dimissorial letters are the authorization a bishop or other competent ordinary gives to another bishop to confer Orders on his subject. Ecclesiastical law has traditionally required that ordination be received from one's proper bishop or upon his authorization [cf. Codex iuris canonici (repr. Graz 1955) c. 1015 §1, Codex canonum ecclesiarium orientalium, c. 747]. The present legislation concerning dimissorials is basically that of the Council of Trent.
For the ordination of diocesans, dimissorials may be granted by the proper bishop after he has taken possession of his diocese. The diocesan administrator of a vacant diocese, with the consent of the diocesan college of consultors, may also grant dimissorial letters [Codex iuris canonici (Graz 1955) c. 1018, Codex canonum ecclesiarium orientalium, c. 750]. Usually these letters are sent to a designated bishop, although they may be given in such a manner that the candidate may be ordained by any bishop of the same church sui iuris who is in communion with the Holy See. Exceptionally, the Eastern code allows for an ordinand's proper bishop to send dimissorials to a bishop of another church sui iuris, with the condition that the bishop obtain certain permissions before issuing the letters (Codex canonum ecclesiarium orientalium, cc. 752, 748 §2).
Latin religious who are members of clerical institutes or societies of pontifical right cannot be licitly ordained by any bishop without dimissorial letters from their own major superiors. Superiors of such institutes or societies can never issue dimissorials for major orders on behalf of their subjects who are not definitively incorporated [Codex iuris canonici (Graz 1955) c. 1019]. The superiors of Eastern monasteries sui iuris and major superiors of Eastern orders, congregations, and societies of common life according to the manner of religious may issue dimissorial letters in accord with their proper law (Codex canonum ecclesiarium orientalium, cc. 472; 537 §1; 560 §1).
In the case of both diocesans and religious, dimissorials must be issued for the ordination of a definite subject to certain specific orders. They should also include mention of the fact that the testimonials required according to Codex iuris canonici, cc. 1050 and 1051 or Codex canonum ecclesiarium orientalium, c. 769 have been obtained [Codex iuris canonici, c. 1020, Codexcanonum ecclesiaarium orientalium, c. 751]. Ordinarily, dimissorial letters are granted in writing, but oral concession is possible.
Bibliography: f. claeys bouuaert, Dictionnaire de droit canonique, ed. r. naz, 7 v. (Paris 1935–65) 4:1244–50. j. j. quinn, Documents Required for the Reception of Orders (Catholic University of America Canon Law Studies 266; Washington 1948).