22.—(1) A woman shall in accordance with the following provisions of this regulation, provide the person who is liable to pay her statutory maternity pay with evidence as to—
(a)the week in which the expected date of confinement occurs, and
(b)where her entitlement to statutory maternity pay depends upon the fact of her confinement, the week in which she was confined.
(2) For the purpose of paragraph (1)(b) a certificate of birth shall be sufficient evidence that the woman was confined in the week in which the birth occurred.
(3) The evidence shall be submitted to the person who will be liable to make payments of statutory maternity pay not later than the end of the third week of the maternity pay period so however that where the woman has good cause the evidence may be submitted later than that date but not later than the end of the 13th week of the maternity pay period.
(4) For the purposes of paragraph (3) evidence contained in an envelope which is properly addressed and sent by prepaid post shall be deemed to have been submitted on the day on which it was posted.