*915To avoid dismissal for failing to timely serve the complaint after a demand had been made pursuant to CPLR 3012 (b), and to be entitled to an extension of time to serve the complaint under CPLR 3012 (d), the plaintiffs had to demonstrate both a reasonable excuse for the delay and a potentially meritorious cause of action (see Tewari v Tsoutsouras, 75 NY2d 1, 12 [1989]; Grace v Follini, 80 AD3d 560 [2011]; Roccanova v Aussino [USA], Inc., 76 AD3d 522 [2010]; Juseinoski v Board of Educ. of City of N.Y., 15 AD3d 353, 357 [2005]). Here, the plaintiffs failed to provide an affidavit of merit from a person possessing personal knowledge of the facts underlying the action (see Tewari v Tsoutsouras, 75 NY2d at 12; Juseinoski v Board of Educ. of City of N.Y., 15 AD3d at 356). Accordingly, the Supreme Court should have denied the plaintiffs’ motion, in effect, pursuant to CPLR 3012 (d) to extend the time to serve the complaint, and should have granted the defendants’ cross motion pursuant to CPLR 3012 (b) to dismiss the action for failure to timely serve the complaint.
The parties’ remaining contentions have been rendered academic in light of our determination. Rivera, J.E, Dickerson, Chambers and Austin, JJ., concur.