It was created on 4 April 2005, replacing the former Immigration Appellate Authority (IAA), and fell under the administration of the Tribunals Service.
Immigration Adjudicators considered appeals against decisions made by Immigration Officers, entry clearance officers and the Home Secretary, with permanent centres in Islington in inner London, Hatton Cross, Birmingham, Leeds, Manchester and Glasgow.
For an indefinite period requests for reconsideration orders will be considered initially by Immigration judges of the AIT ("the filter"); should the request be refused a party can opt into the High Court or Court of Session.
A party cannot say that he seeks a re-hearing of the facts or that the factual conclusions reached by the Immigration Judge are wrong.
He can only seek reconsideration if the Immigration Judge has misdirected himself in law, failed to consider relevant material, considered irrelevant material, or erred in his fact-finding to the extent that the findings are irrational and therefore amount to an error of law.
Most of these cases are heard at the old IAT, at Field House, Bream's Buildings, just off Chancery Lane in central London.
If they conclude that there was a material error of law, they may either reconsider the case in full or in part themselves, or (more usually) order that it be re-heard at a later date.
After a re-hearing, or if the AIT which hears a case for the first time has a 3 or more members, the decision may only be challenged by an appeal to the Court of Appeal (Civil Division) in England and Wales, or the Court of Session (Inner House) in Scotland.