N.Y. Comp. Codes R. & Regs. tit. 22, § 1245.5 – Electronic filing and service.

(a) All authorized e-filers who have entered information for a particular cause as set forth in sections 1245.3(a), (c) or (d) or 1245.4(d) of this Part shall thereafter e-file and be served electronically in that matter.
(b) Prior to the expiration of the 20-day period for entry of information described in section 1245.3(d) of this Part, filing and service of documents by, and service upon, parties who have not entered such information shall be in hard copy.
(c) Upon expiration of the 20-day period for entry of information described in section 1245.3(d) of this Part, service and filing by and upon all parties other than exempt attorneys and exempt litigants shall be by e-filing. Thereafter, an attorney who has neither entered information nor given notice as an exempt attorney pursuant to section 1245.4(a)(2) of this Part shall be deemed served with any e-filed document.
(d) At all times, service by and upon, and filing by, exempt attorneys and exempt litigants shall be in hard copy. E-filers shall e-file proof of any service made in hard copy.
(e) Site instructions.
Technical instructions for e-filing documents shall be set forth on the NYSCEF site (www.nycourts.gov/efile).
(f) Formatting.
In addition to compliance with the court’s general rules for document formatting, e-filed documents filed pursuant to this Part shall comply with the formatting requirements set forth in attachment A.