Reference

New York API county codes

Every New York API well number starts with 31, the state code. The next three digits are the county code, one of the 62 listed below, so a number beginning 31-001 belongs to a well in Albany County.

To decode a whole number, including the sidetrack and completion digits, paste it into the API well number decoder.

How to read a New York API number

31State: New York
001County: Albany
12345Well, unique within the county

The first ten digits identify one well. Two more digits can follow for a sidetrack, and two after that for a later completion. The county is the one where the well starts at the surface, so a horizontal well that crosses a county line keeps its surface county's code. A few state regulators assign the producing county instead, so the state record is the final word on a well near a boundary.

All 62 New York counties

County code County API numbers start
001 Albany 31-001-
003 Allegany 31-003-
005 the Bronx 31-005-
007 Broome 31-007-
009 Cattaraugus 31-009-
011 Cayuga 31-011-
013 Chautauqua 31-013-
015 Chemung 31-015-
017 Chenango 31-017-
019 Clinton 31-019-
021 Columbia 31-021-
023 Cortland 31-023-
025 Delaware 31-025-
027 Dutchess 31-027-
029 Erie 31-029-
031 Essex 31-031-
033 Franklin 31-033-
035 Fulton 31-035-
037 Genesee 31-037-
039 Greene 31-039-
041 Hamilton 31-041-
043 Herkimer 31-043-
045 Jefferson 31-045-
047 Brooklyn 31-047-
049 Lewis 31-049-
051 Livingston 31-051-
053 Madison 31-053-
055 Monroe 31-055-
057 Montgomery 31-057-
059 Nassau 31-059-
061 New York 31-061-
063 Niagara 31-063-
065 Oneida 31-065-
067 Onondaga 31-067-
069 Ontario 31-069-
071 Orange 31-071-
073 Orleans 31-073-
075 Oswego 31-075-
077 Otsego 31-077-
079 Putnam 31-079-
081 Queens 31-081-
083 Rensselaer 31-083-
085 Richmond 31-085-
087 Rockland 31-087-
089 St. Lawrence 31-089-
091 Saratoga 31-091-
093 Schenectady 31-093-
095 Schoharie 31-095-
097 Schuyler 31-097-
099 Seneca 31-099-
101 Steuben 31-101-
103 Suffolk 31-103-
105 Sullivan 31-105-
107 Tioga 31-107-
109 Tompkins 31-109-
111 Ulster 31-111-
113 Warren 31-113-
115 Washington 31-115-
117 Wayne 31-117-
119 Westchester 31-119-
121 Wyoming 31-121-
123 Yates 31-123-

County names are the US Census names for these codes. The API standard does not promise the two match, so we checked them against state well records. Across 35 states, where this table names a county it matched the one the agency recorded on 85,091 of 85,100 wells. Offshore state and federal waters use their own pseudo-county codes, which are not listed here.

Finding the well itself

The API number stops at the county. It does not hold the well's coordinates, lease, survey section or operator. Those sit in the well record, which you find by searching the full number in the state agency's system. Search it at the New York oil and gas regulator.

Frequently asked questions

What is the API state code for New York?

31. API state codes run alphabetically from 01 for Alabama to 49 for Wyoming, then 50 for Alaska and 51 for Hawaii. They are not the Census FIPS state codes, which is a common source of wrong lookups.

How do I find the county from a New York API number?

Read digits three to five and find them in the table on this page. In 31-001-12345, the county code is 001, which is Albany County. If the code is missing from the table, it is usually an offshore area rather than an onshore county.

Does a New York API number give the well's exact location?

No. The number stops at the county. Coordinates, the lease and the survey location are in the well record held by the state agency, which you search with the full API number.

State codes: American Petroleum Institute Bulletin D12A well numbering standard. County names: US Census county FIPS names, checked against state well records. Reference generated .

How to cite this page

Sources: American Petroleum Institute Bulletin D12A well numbering standard; US Census county FIPS codes.

TetraSoft. (2026). New York API county codes. Reference generated 2026-09-24. https://tetrasoftco.com/tools/api-county-codes/new-york/