Ordered that the order is affirmed, without costs or disbursements.
The issues raised by the father on this appeal are not reviewable. The Family Court properly denied the father's objections on the ground that he failed to file proof of service of a copy of the objections on the mother. Family Court Act § 439 (e) provides, in pertinent part, that "[a] party filing objections shall serve a copy of such objections upon the opposing party," and that "[p]roof of service upon the opposing party shall be filed with the court at the time of filing of objections and any rebuttal." By failing to file proof of service of a copy of his objections on the mother, the father failed to fulfill a condition precedent to filing timely written objections to the Support Magistrate's order ( see Matter of Chambers v Chambers, 305 AD2d 672, 673; Matter of Rinaldi v Rinaldi, 239 AD2d 506).