8 CFR § 1241.1 - Final order of removal.
(a) Upon dismissal of an appeal by the Board of Immigration Appeals;
(b) Upon waiver of appeal by the respondent;
(c) Upon expiration of the time allotted for an appeal if the respondent does not file an appeal within that time;
(f) If an immigration judge issues an alternate order of removal in connection with a grant of voluntary departure, upon overstay of the voluntary departure period, or upon the failure to post a required voluntary departure bond within 5 business days. If the respondent has filed a timely appeal with the Board, the order shall become final upon an order of removal by the Board or the Attorney General, or upon overstay of the voluntary departure period granted or reinstated by the Board or the Attorney General.