N.Y. CVP Law § 308

§ 308. Personal service upon a natural person. Personal service upon\na natural person shall be made by any of the following methods:\n 1. by delivering the summons within the state to the person to be\nserved; or\n 2. by delivering the summons within the state to a person of suitable\nage and discretion at the actual place of business, dwelling place or\nusual place of abode of the person to be served and by either mailing\nthe summons to the person to be served at his or her last known\nresidence or by mailing the summons by first class mail to the person to\nbe served at his or her actual place of business in an envelope bearing\nthe legend "personal and confidential" and not indicating on the outside\nthereof, by return address or otherwise, that the communication is from\nan attorney or concerns an action against the person to be served, such\ndelivery and mailing to be effected within twenty days of each other;\nproof of such service shall be filed with the clerk of the court\ndesignated in the summons within twenty days of either such delivery or\nmailing, whichever is effected later; service shall be complete ten days\nafter such filing; proof of service shall identify such person of\nsuitable age and discretion and state the date, time and place of\nservice, except in matrimonial actions where service hereunder may be\nmade pursuant to an order made in accordance with the provisions of\nsubdivision a of section two hundred thirty-two of the domestic\nrelations law; or\n 3. by delivering the summons within the state to the agent for service\nof the person to be served as designated under rule 318, except in\nmatrimonial actions where service hereunder may be made pursuant to an\norder made in accordance with the provisions of subdivision a of section\ntwo hundred thirty-two of the domestic relations law;\n 4. where service under paragraphs one and two cannot be made with due\ndiligence, by affixing the summons to the door of either the actual\nplace of business, dwelling place or usual place of abode within the\nstate of the person to be served and by either mailing the summons to\nsuch person at his or her last known residence or by mailing the summons\nby first class mail to the person to be served at his or her actual\nplace of business in an envelope bearing the legend "personal and\nconfidential" and not indicating on the outside thereof, by return\naddress or otherwise, that the communication is from an attorney or\nconcerns an action against the person to be served, such affixing and\nmailing to be effected within twenty days of each other; proof of such\nservice shall be filed with the clerk of the court designated in the\nsummons within twenty days of either such affixing or mailing, whichever\nis effected later; service shall be complete ten days after such filing,\nexcept in matrimonial actions where service hereunder may be made\npursuant to an order made in accordance with the provisions of\nsubdivision a of section two hundred thirty-two of the domestic\nrelations law;\n 5. in such manner as the court, upon motion without notice, directs,\nif service is impracticable under paragraphs one, two and four of this\nsection.\n 6. For purposes of this section, "actual place of business" shall\ninclude any location that the defendant, through regular solicitation or\nadvertisement, has held out as its place of business.\n