An Application for Leave to File a Second or Successive Motion to Vacate, Set Aside or Correct Sentence by a Prisoner in Federal Custody is an administrative procedure that applies to persons who have exhausted all of their direct appeals in the federal criminal justice system, and who wish to challenge their convictions or sentences. There are two types of these applications: a “second or successive” application, and an “initial” application. A “second or successive” application is used to challenge a conviction or sentence on the basis of newly discovered evidence, a change in the law, or other reasons that could not have been raised in the direct appeal. An “initial” application is used for those who have exhausted their direct appeals and who are seeking to challenge their convictions or sentences on the basis of a constitutional violation. Both types of applications require a prisoner to provide detailed information about their case and the grounds upon which they are seeking relief. In addition, the application must be accompanied by a motion to vacate, set aside, or correct the sentence, along with supporting legal arguments, and evidence that the prisoner has exhausted all direct appeals. If the application is successful, the court may grant the motion and vacate, set aside, or correct the sentence.