https://www.slab.org.uk/guidance/expert-witnesses-rates-travel-and-other-expenses/
Unless otherwise approved, the rates should be charged having regard to the fees prescribed:
Necessary travelling time from residence or place of business shall be included in the computing the fee payable. Where a locum tenens is engaged or arranged, payment will again be on the basis of the professional witness rates:
The breakdown of the expert’s costs may include the following items relating to travel and other expenses. We can grant cover or inform you about what cannot be covered at this stage of seeking approval for the work. This avoids work being carried out in a manner we cannot pay for and which can cause difficulties at the account payment stage.
Experts who charge in excess of the recommended Crown rates can only be paid for time travelling at half their hourly rate. Where a higher rate is sought will restrict the grant and let you know.
Where experts travel by car, the mileage rate is 45p per mile and is paid as an outlay and does not form part of the grant of prior approval.
Experts using public transport should use the most economical form of transport. All train fares will be paid at Standard Class. Fares are paid as outlays and do not form part of the grant of prior approval.
Where an overnight stay is necessary and the amount sought (including subsistence of breakfast and dinner) exceeds £125.14 (the amount we pay counsel), then a reasonable explanation should be given for this, such as the geographical area and/or the particular time of year.
We will pay for an evening meal up to £20 and will not pay for alcohol and other sundries.
We do not pay these or any other administrative charges.
When VAT is included in the application for prior approval this will not from part of any grant made. VAT is an outlay and is paid at the accounts stage. You should tell a solicitor this and restrict the amount you grant.
Approval for an expert witness
Additional guidance on specific expert witnesses – defence post mortems, drug experts, psychologists, psychiatrists, forensic accountants