BS ISO 24366:2021 pdf download – Financial services — Natural person identifier (NPI)
This document specifies a machine-readable, unambiguous natural person identifier (NPI) and the relevant reference data to uniquely identify the natural person relevant to any financial transaction rather than the personal identifying information.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3166-1, Codes for the representation of names of countries and their subdivisions — Part 1: Country code
ISO/IEC 7064, Information technology — Security techniques — Check character systems
ISO 8601-1, Date and time — Representations for information interchange — Part 1: Basic rules
ISO 17442 (all parts), Financial services — Legal entity identifier (LEI)
ICAO 9303, Machine Readable Travel Documents
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at
— IEC Electropedia: available at
4 Structure of the natural person identifier
This document uses the following conventions for data element representations:
a) Character representations:
— n: digits (numeric characters 0 to 9 only);
— c: upper-case alphanumeric characters (A to Z and 0 to 9 only).
b) Length indications:
— nn!: fixed length;
— nn: maximum length.
The format of the NPI shall be
— 13!c2!n.
The NPI consists of 15 characters decomposed as follows:
— characters (13!c) without separators or “special” characters;
— the 14th and 15th characters (2!n) shall be the check digit pair, as calculated based on the procedure defined in this document.
5 Check digits
5.1 General
The check digits shall be calculated based on the simplified procedure defined in ISO/IEC 7064 (refer to MOD 97-10 for the simplified check digit calculation) after the conversion of the (leftmost) 13 alphanumeric characters into a character string consisting only of digits. The check digits are used to verify the NPI.
Valid check digit pairs are in the range of [02 .. 98]. 00, 01 and 99 are not valid NPI check digit pairs.
If the check digits have been calculated correctly, when the entire 15-character NPI is converted to numbers following the process described in step 1 of 5.2 and divided by 97 as described in step 3 of 5.2,the remainder shall be “1”.
5.2 Calculating the check digits
Step 1: Any letters in the 13-character string shall be converted to digit pairs in accordance with ISO/IEC 7064 (MOD 97-10).
Step 2: Two zeros shall be appended to the resulting string at the rightmost positions.
Step 3: A Euclidian division of the resulting number by 97 shall be performed to determine the remainder.
Step 4: The remainder shall be subtracted from 98 to determine the check digit pair.
Step 5: The check digit pair shall be appended to the original 13-character string to arrive at the NPI.
See Annex A for examples
6 Natural person identifier data record
The NPI data record shall be composed of the data attributes shown in Table 1.BS ISO 24366 pdf download.