https://www.slab.org.uk/guidance/outlays-for-ordinary-witnesses-cited-to-attend-court/
If the witness has lost earnings as a result of attending court, we may reimburse the net loss. The witness should provide you with a letter from their employer. This should be on letter headed paper and signed by the employer and state the exact net loss of earnings. If the witness is self-employed we will require a letter from their accountant.
When travelling, the most economical form of transport should be used. All train and air fares will be paid at Standard Class. The witness should retain all tickets to be submitted with the account. If the witness uses their own car we will only pay their out of pocket expenses. Typically, this will be calculated on the HMRC rates for fuel costs.
Where an overnight stay cannot be avoided, we will pay:
We will not pay for any alcohol, newspapers, telephone calls or sundries. We will only make payment of accommodation/subsistence costs where an itemised receipt is provided. Credit card and bank statements will not be accepted as proof of payment.
If a witness employs a baby-sitter or child minder, they will be reimbursed only if these services are not normally required. If the child minder is registered with the Local Authority the child minder’s registration number is required.
The hourly rates payable to registered child minders and non-registered child minders will be allowed at the following rates: