An applicant can reapply or challenge an AR decision by filing a Judicial Review (JR). If deemed admissible by the High Court, the JR considers whether the decision should be reversed on grounds of illegality, irrationality (unreasonableness), procedural impropriety, and/or legitimate expectation. A JR is preceded by service to the Home Office of a pre-action protocol (PAP) letter. In fact, in the PAP letter the applicant (in practice their legal representative) sets out the grounds for challenge, the remedy sought, and the timescale for the Home Office to respond (normally 14 days) before the lodging a JR.