What is Prior Authority?
Prior authority is the Legal Aid Agency's advance approval for expert witness expenditure in circumstances where approval is required or sought. The published rate schedule remains the starting point for the relevant expert category and location. Where a suitably qualified expert cannot be instructed at the applicable rate — whether because of specialist expertise, the complexity of the case or the volume of material to be reviewed — a well-evidenced prior-authority request may be appropriate before 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 may be appropriate in several situations. Understanding which applies to the case determines the urgency of the request and the supporting evidence 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.
A request may be appropriate where the cost is unusual or unusually large, the proposed rate is outside the applicable schedule, or the instruction has no applicable prescribed or guideline rate. The £100 figure in the criminal guidance relates to interim-payment eligibility under the Litigators’ Graduated Fee Scheme; it is not a universal prior-authority 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 current criminal rates for expert disciplines most frequently instructed by criminal defence solicitors. It applies to cases started on or after 30 September 2022. London status depends on the expert’s registered office. Solicitors should verify the current rate against LAA guidance before submitting a request.
| Discipline | Non-London rate | London rate | Notes |
|---|---|---|---|
| Psychiatrist | £124.20/hr | £82.80/hr | Criminal cases started on or after 30 September 2022 |
| Psychologist | £107.64/hr | £82.80/hr | Criminal cases started on or after 30 September 2022 |
| Neurologist | £141.00/hr | £83.00/hr | Criminal cases started on or after 30 September 2022 |
| Forensic Scientist | £104.00/hr | £83.00/hr | Criminal cases started on or after 30 September 2022 |
| Toxicologist | £124.20/hr | £82.80/hr | Criminal cases started on or after 30 September 2022 |
| Computer Expert | £83.00/hr | £83.00/hr | Criminal cases started on or after 30 September 2022 |
| Drug Expert | £83.00/hr | £83.00/hr | Criminal cases started on or after 30 September 2022 |
Source: LAA expert-witness guidance and June 2026 crime guidance. Verify the current rate and application route before submitting a request.
Completing the CRM4 Application
Criminal and family cases use different LAA routes. For criminal legal-aid cases, use the LAA digital Apply for prior authority service. For family and civil cases, submit the request through CCMS. In either route, provide a clear estimate, expert CV and case-specific justification.
A complete request should identify the case, the precise instruction, the expert category and office location, the proposed rate and hours, and the evidence supporting any requested departure from the applicable schedule. Missing or vague information creates avoidable 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 specialist qualifications, medico-legal experience and relevant court work. Where a requested rate exceeds the applicable schedule, explain why the case needs the stated level of expertise.
State the proposed hourly rate, registered office location and estimated hours for each stage. Support the request with case-specific evidence: complexity, records volume, a specialist sub-specialty, availability within the court timetable or evidence of reasonable attempts to obtain alternative quotes.
Attach the expert's written fee estimate, broken down by stage. The estimate should match the rate, location, hours and scope stated in the request. Discrepancies are a common cause of delay. Expert Witness UK provides an itemised estimate and CV to support the applicable LAA route.
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 for the relevant prior-authority route. When you instruct an expert through our agency, you receive an itemised fee estimate, a current CV highlighting specialist qualifications and medico-legal experience, and supporting information explaining the proposed scope and rate.
All experts on our panel are instructed at rates that reflect their qualifications and the complexity of the work. Where the applicable scheduled rate is appropriate, we will say so. Where a request is appropriate, we provide the supporting material before the work begins. Advance approval cannot be granted after the work has been completed.
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 current rate and correct LAA route. For drug and alcohol expert witnesses, the applicable category depends on the type of instruction and proposed expert.
How to Apply for Prior Authority — Step by Step
Check current LAA guidance for the expert category, registered office location, proceedings type and rate schedule. Consider whether the proposed rate or cost is outside the schedule, unusual or unusually large, or needs advance approval.
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.
For criminal cases, use the LAA digital service; for family cases, use CCMS. Explain why the requested rate or cost is appropriate, giving the expert category, office location, specialist expertise, complexity, records volume and any alternative-quote evidence.
Submit all supporting documents and allow time for further information requests. Where advance approval is sought, do not start the work before a decision has been received. Keep the estimate, decision and approved scope on the case 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.