Recovery certificates cannot be disputed before the Recovery Officer; issuing authority may correct, stay, amend, or withdraw them. Section 130 provides that a certificate issued to a Recovery Officer is immune from challenge by the employer before the Recovery Officer; the Authorised Officer may withdraw the certificate or correct clerical or arithmetical errors and must notify the Recovery Officer. The Authorised Officer may grant time for payment, requiring the Recovery Officer to stay proceedings, must inform the Recovery Officer of payments or time granted, and must stay or amend/withdraw recovery where appellate modification reduces the demand until finality.