(a) Scope.--The provisions of this section apply to a witness served with a subpoena to testify before any government unit (except the minor judiciary) or before the Philadelphia Municipal Court, but do not affect:
(1) The right of a witness who gives expert testimony to receive additional per diem compensation therefor.
(2) The compensation of a witness from another jurisdiction who appears to testify in a criminal proceeding in this Commonwealth by virtue of process issued under the authority of such other jurisdiction.
(b) Compensation.--Every witness, except a salaried police officer attending a coroner's inquest during working hours, shall be paid at the rate of $5 per day during the necessary period of attendance. A witness under the act of March 30, 1937 (P.L.115, No.40), known as "The First Class City Permanent Registration Act" shall be paid at the rate of $20 per day.
(c) Travel.--Every witness, except a salaried police officer attending a coroner's inquest during working hours, shall be paid mileage at the rate of 7¢ for each mile circular actually and necessarily travelled between the place named in the subpoena and the place of residence of the witness.
(d) Lodging and subsistence.--When a matter is prolonged from one day to the next a witness necessarily present on both days who resides more than 50 miles by the usually-travelled route from the place named in the subpoena and who remains there overnight shall be paid commutation of lodging and subsistence for each such night in an additional amount equal to the per diem witness fee.
(e) Adjournments and postponements.--When a matter is adjourned, continued or postponed for more than one day, or is prolonged from one week to the next, a witness necessarily present both before and after such interval and who returns to the place of residence of the witness during such interval shall be paid one additional travel allowance for each such interval.
(f) Multiple matters.--A witness necessarily present for more than one matter at the same place during any day shall receive only one payment for compensation and expenses under this section.
(g) Witness not called.--A witness who attends any matter under subpoena, but who is not called to testify therein, shall receive the same compensation and expenses as if actually called to testify.
(h) Payment at time of service of subpoena.--At the time a witness is served with a subpoena for any civil matter the witness shall, upon demand, be paid the witness fee for one day and travel expense provided in this section.
(i) Certification.--The person disbursing compensation and expenses to a witness under this section may require that the witness first certify under 18 Pa.C.S. § 4904(b) (relating to statements "under penalty") that the compensation and expenses paid do not exceed the amount specified by this section.