What is Prior Authority?
Prior authority is the Legal Aid Agency's advance approval for expert witness expenditure that exceeds the codified rates published under the Criminal Legal Aid (Remuneration) Regulations 2013. The codified rates represent the maximum the LAA will pay for a given expert discipline without prior approval. Where a suitably qualified expert cannot be instructed at the codified rate — whether because of their specialist sub-specialty, the complexity of the case, or the volume of material to be reviewed — the solicitor must obtain prior authority before any work begins.
The requirement for prior authority flows from the Legal Aid, Sentencing and Punishment of Offenders Act 2012 (LASPO) and the accompanying Regulations. Its purpose is to control public expenditure on legal aid whilst preserving access to justice in cases where the standard rates are genuinely insufficient. The LAA's position is that prior authority is not a rubber stamp — applications are assessed on their merits, and a poorly prepared CRM4 will be refused.
The distinction between prior authority and prior approval matters. Prior authority relates specifically to the rate or cost of an expert. Prior approval, by contrast, is required for certain categories of disbursement in civil legal aid cases. In criminal proceedings, the relevant mechanism is always prior authority via the CRM4 form.
When Prior Authority is Required
Prior authority is required in three distinct situations. Understanding which applies to your case determines both the urgency of the application and the level of justification the LAA will expect.
The most common trigger. If the expert's proposed hourly rate exceeds the published codified rate for their discipline, prior authority is required for the excess. The LAA will pay the codified rate automatically on assessment; it will only pay the higher rate if prior authority was granted before the work was done.
In magistrates' court proceedings, prior authority is required where the total estimated cost of the expert's work exceeds £100. In Crown Court proceedings, the threshold is set by the applicable graduated fee scheme. Where the instruction is straightforward and the codified rate applies, a brief CRM4 is still required if the total cost crosses the threshold.
Some specialist disciplines — for example, a highly specialist forensic linguist or a consultant in a rare sub-specialty — have no published codified rate. In these cases, the entire fee requires prior authority, and the CRM4 must explain why no expert at a codified rate is available or suitable.
LAA Codified Rates by Discipline
The table below sets out the current codified rates for the expert disciplines most frequently instructed in criminal defence and family proceedings. These rates are set by the Criminal Legal Aid (Remuneration) Regulations 2013 (as amended) and are reviewed periodically by the LAA. Solicitors should always verify the current rates on the LAA's published fee guidance before submitting a CRM4.
| Discipline | Report Prep Rate | Court Attendance Rate | Key Qualifications |
|---|---|---|---|
| Consultant Psychiatrist | £90/hr | £90/hr | Section 12 approved; MRCPsych/FRCPsych |
| Consultant Psychologist | £72/hr | £72/hr | HCPC registered; CPsychol preferred |
| Consultant Neurologist | £90/hr | £90/hr | GMC specialist register; ABN member |
| Forensic Scientist | £72/hr | £72/hr | CSFS/FSR registered; ISO 17025 lab |
| Toxicologist | £72/hr | £72/hr | CSFS registered; UKIAT/UKIAFT member |
| CCTV / Digital Forensics | £72/hr | £72/hr | NPCC APP compliant; BCS/CEng |
| Drug & Alcohol Specialist | £72/hr | £72/hr | GMC/HCPC; FSAM/SoHT accredited |
Rates are indicative based on the Criminal Legal Aid (Remuneration) Regulations 2013 (as amended). Verify current rates at gov.uk before submitting any CRM4 application.
Completing the CRM4 Application
The CRM4 is the standard form for prior authority applications in criminal proceedings. It is submitted through the LAA's Client and Cost Management System (CCMS). Where a firm is not yet registered on CCMS, paper applications are accepted, though CCMS is the LAA's preferred route and processing times are faster.
The form has five key sections. Each must be completed with precision; the LAA's caseworkers assess applications against a checklist, and missing or vague information is the most common reason for refusal or delay.
Set out the case reference, the court, the stage of proceedings, and the nature of the charge or application. Be specific — 'Crown Court trial for s.18 GBH with a psychiatric defence' is more useful to the LAA caseworker than 'criminal proceedings'.
Describe precisely what the expert is being asked to do. Specify the type of report (e.g., psychiatric assessment for fitness to plead under the Pritchard criteria, psychological risk assessment for sentencing, neuropsychological assessment for diminished responsibility). Reference the relevant legal framework — CrimPR Rule 19, the Mental Health Act 1983, or the Criminal Procedure (Insanity) Act 1964 as appropriate.
Attach the expert's full CV. Highlight their specialist qualifications (e.g., FRCPsych, Section 12 MHA approval, HCPC registration), their medico-legal experience, and any relevant publications or court experience. The LAA will not accept a rate above the codified level for an expert who does not demonstrably possess specialist expertise beyond the standard for their discipline.
State the proposed hourly rate and the estimated number of hours for each stage of work. The justification must be specific and evidence-based. Acceptable justifications include: the complexity of the psychiatric presentation, the volume of records to be reviewed (specify the number of pages or bundles), the absence of any expert at the codified rate who is available within the court timetable, or the need for a highly specialist sub-specialty (e.g., a forensic neuropsychiatrist rather than a general consultant psychiatrist).
Attach the expert's written fee estimate, broken down by stage. The estimate should match the figures in the CRM4. Discrepancies between the CRM4 and the fee estimate are a common cause of delay. Expert Witness UK provides a standardised fee estimate template that meets the LAA's requirements.
Prior Authority in Family Proceedings
Family proceedings introduce an additional layer of procedural complexity. Under the Children and Families Act 2014 s.13 and FPR Part 25, the court must give permission for expert evidence before it can be obtained. The permission application is made to the court, not the LAA, and the court applies the test of whether the expert evidence is necessary to assist the court to resolve the proceedings justly.
Once the court grants permission, the LAA's prior authority process runs in parallel. The LAA's Family Graduated Fee Scheme sets out the rates payable for expert reports in public law children cases. Where the proposed rate exceeds the scheme rate, a prior authority application must be submitted to the LAA before the expert begins work. The court's permission does not bind the LAA on the question of rate.
In private law family proceedings, the funding landscape differs again. Where the client is publicly funded, the LAA's prior authority requirements apply in the same way as in public law cases. Where the client is privately funded, there is no LAA prior authority requirement, and the solicitor and client agree the expert's fees directly. Expert Witness UK can instruct experts on both a legally aided and privately funded basis.
For family law cases involving psychological or psychiatric assessments of capacity, parental functioning, or child welfare, see our guide to family law expert witnesses and the psychology expert witness services page for the specific assessments available.
What to Do When Prior Authority is Refused
Refusal of a prior authority application does not end the matter. The LAA's decision is subject to a formal review process, and a well-argued review application succeeds in a significant proportion of cases where the original CRM4 was insufficiently detailed.
The review must be requested in writing within 21 days of the refusal notice. The review is conducted by a different LAA caseworker. Submit additional evidence with the review — for example, a letter from the expert explaining why the complexity of the case justifies the higher rate, or evidence that no expert at the codified rate is available within the court timetable.
If the review is also refused, the solicitor may apply to the court for a direction that the expert evidence is necessary and that the proposed rate is reasonable. The court's direction does not bind the LAA, but it carries significant weight in any subsequent costs assessment. Crown Court judges are generally sympathetic to applications where the LAA has refused funding for genuinely necessary expert evidence.
In cases where the refusal of prior authority would breach the client's rights under the European Convention on Human Rights — for example, where the right to a fair trial under Article 6 ECHR requires expert evidence that cannot be funded at the codified rate — the solicitor may apply for exceptional case funding under LASPO s.10. This is a high threshold, but it is available where the case genuinely requires it.
How Expert Witness UK Supports Prior Authority Applications
Expert Witness UK provides solicitors with the documentation needed to complete a CRM4 application quickly and accurately. When you instruct an expert through our agency, you receive a standardised fee estimate in the format the LAA expects, a current CV highlighting the expert's specialist qualifications and medico-legal experience, and a brief supporting letter from the expert explaining why the proposed rate reflects the complexity of the instruction.
All experts on our panel are instructed at rates that reflect their qualifications and the complexity of the work. Where the codified rate is sufficient, we will say so. Where it is not, we will provide the documentation needed to support a prior authority application before any work begins. We do not instruct experts to begin work before prior authority is confirmed.
For criminal defence cases involving psychological expert witnesses, psychiatric expert witnesses, neurological expert witnesses, or forensic expert witnesses, contact our admin team to discuss the prior authority position before submitting your CRM4. For drug and alcohol expert witnesses, the codified rate position depends on whether the instruction is to a consultant psychiatrist, a clinical psychologist, or a forensic toxicologist.
How to Apply for Prior Authority — Step by Step
Check the current LAA fee guidance to identify the codified rate for the expert's discipline. If the expert's proposed rate exceeds the codified rate, or if the total estimated cost exceeds the applicable threshold, prior authority is required before any work begins.
Request a written fee estimate from the expert setting out their hourly rate, the estimated number of hours for each stage of work, and the total estimated cost. Attach the expert's full CV, including qualifications, professional body membership, and medico-legal experience. Expert Witness UK provides both documents as standard.
Log in to the LAA's CCMS and complete the CRM4. Set out clearly why the codified rate is insufficient — the expert's specialist sub-specialty, the complexity of the issues, the volume of material to be reviewed, or the absence of any expert at the codified rate who is available and suitably qualified. Vague justifications are the most common reason for refusal.
Submit the CRM4 with all supporting documents. The LAA aims to process prior authority applications within five working days. Do not instruct the expert to begin work until written confirmation of prior authority has been received. Keep a copy of the approval notice on the file.
If the expert's work subsequently exceeds the approved scope — for example, because additional records are disclosed — a further prior authority application must be submitted before the additional work is carried out. Inform the expert immediately of the approved scope and instruct them not to exceed it without further authorisation.