The UK Border Agency (UKBA) is wasting £75 million per year by detaining migrants who are ultimately released. Limited detention space could be more efficiently used if case owners “get it right” initially by only detaining migrants who can be deported within a lawful and reasonable period. This change could be made through minor revisions to Chapter 55 of the Enforcement Instructions and Guidance to ensure that prospects of removal are thoroughly assessed alongside risks of reoffending and absconding. Ministers should ask the UKBA to revise the guidance to balance likelihood of removal against these risks.