This re-certification process is handled by the New York State Police and is separate from any transactions performed in the County pistol permit office.
Changes to New York State Penal Law require that a person who has been issued a license to possess or carry a firearm re-certify his/her status every five years. A copy of the informational letter from the New York State Police is available here. NYSP re-certification letter
If your permit was issued before January 15, 2013, the deadline to submit your re-certification is January 31, 2018 and every five years thereafter. If your permit was issued on or after January 15, 2013, the deadline to re-certify is five years after the date the permit was issued and every five years thereafter. As a permit holder, it is your responsibility to re-certify your permit whether you receive a notification letter or not.