However, the default judgment must, nevertheless, be vacated, as the District Court Clerk did not have the authority to enter a judgment against defendant pursuant to CPLR 3215(a), since the damages sought against defendant were not for a “sum certain” and could not be determined without extrinsic proof ( see Vinny Petulla Contr. Corp. v. Ranieri, 94 AD3d 751 ;Stephan B. Gleich & Assoc. v. Gritsipis, 87 AD3d 216, 222–224 ;Pikulin v. Mikshakov, 258 A.D.2d 450, 451 ;General Elec. Tech. Servs. Co. v. Perez, 156 A.D.2d 781, 784  ). In light of the foregoing, the District Court should have granted defendant's motion only to the extent of vacating the default judgment and directing an inquest. Under the circumstances presented, we modify the order by providing that defendant's motion is granted only to the extent of vacating the default judgment and by striking the remaining provisions of the order and replacing them with a provision directing that the sum of $5,703.36 be held in plaintiff's escrow account pending the inquest.