If the witness is a designated public employee, a $275 witness fee must be paid at the time of service of the subpoena unless ordered waived by the court through a Fee Waiver. Designated public employees include: (GC 68097, 68097.2, 68097.4, 68097.5, 68097.55).
If demanded, a witness, other than a designated public employee, is entitled to be paid a $35 witness fee and $0.20 a mile, both ways, prior to attending. (GC 68093, 68097)
Mileage fees are not required if the custodian of record is not required to personally appear.