Bank
Card numbers
Have
you ever thought why most of the time a bank card number is of 16 digits?
Have
you ever observed Visa card numbers always start with 4 and MasterCards with 5?!?
Have
you ever tried to know whether a card number is valid or not?
Do you
know a card number can actually show you what product it is and which bank
issued that card?
Every
Payment Card (Bank Card) is assigned with a number called Bank card number
(also called as Payment card number) by the banks.
Bankcard
number actually consists of three parts,
·
BIN (Bank Identification Number) or IIN (Issuer Identification
Number) – the first 6 digits of a card number (Allocated by American Bankers
Association to Issuers)
o
First digit of the BIN is called as MII (Major Industry Identifier)
– Digits 2, 4, 5 and 6 are assigned
·
Individual Account Number (Allocated by Issuing Banks
·
Check Digit (calculated using Luhn’s Algorithm)
BINs
can be used to identify the Issuer Bank, Issuer Bank’s Country, Interchange
Association of the Card and the Product type.
For
example,
BIN
405028 in this card identifies the card issuer as ‘HDFC Bank’, Country as ‘India’,
Interchange Association as ‘VISA’ and Product Type as ‘Platinum Plus’.
By
Identifying the Country Code, billing currency can be identified.
|
Major
Industry Identifier (MII)
|
Industry
Category
|
0
|
ISO/TC
68
|
1
|
Airlines
|
2
|
Banking/Financial
Institutions
|
3
|
Travel
and Entertainment
|
4
|
Banking/Financial
Institutions
|
5
|
Banking/Financial
Institutions
|
6
|
Banking/Financial
Institutions
|
7
|
Petroleum
|
|
Telecommunications
and Health Care
|
9
|
National
Standard Bodies
|
These
numbers are assigned as per the ISO/IEC 7812 standards which define the
numbering system for the identification of issuers of cards that require an IIN
to operate in an international interchange environment.
ISO/IEC
7812-1:2006 Identification cards - Identification of issuers Part 1: Numbering
system
ISO/IEC
7812-2:2007 Identification cards - Identification of issuers Part 2:
Application and registration procedures
Registration of BINs
Issuers
need to fill the application forms with all details of the industry category (to
assign a MII), intended use of the IIN (Debit card, Credit card, ATM card,
etc.,) and submit it to Sponsoring Authority of the nation. Sponsoring
authorities are the members of ISO.
For
example,
·
BIS - Bureau of Indian Standards
·
ANSI – American National Standards Institute
·
BSI – British Standards Institution
These Sponsoring
Authorities will validate the information provided by the applicant for the
compliance of application with ISO/IEC 7812 standards and if approved, forward
the application to Registration authority. In case of the application being
rejected the sponsoring authorities will write to applicant explaining the reasons
for which the application has been rejected and help the applicant in appealing
process.
Once
the application is received the registration authority assigns a BIN from
appropriate MII and makes an entry in the ISO register of card issuer
identification numbers.
Luhn’s Algorithm - Check Digit
Luhn’s
Algorithm (also called as Modulus 10 algorithm) created by IBM scientist Hans
Peter Luhn is a checksum formula used to validate verities of identification
numbers. This algorithm is helpful in distinguishing the valid numbers from
incorrect or mistyped numbers.
Usually
the check digit is appended to the end of the number to make it a complete
identification number. The check digit can be calculated as below,
·
Double the alternative numbers starting from the number beside
check digit (moving from right to left).
·
If the number is a double digit number after doubling operation,
add the digits of the product.
Card
Number
|
4
|
2
|
6
|
8
|
2
|
8
|
0
|
0
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
X
|
Doubling
|
8
|
|
12
|
|
4
|
|
0
|
|
2
|
|
6
|
|
10
|
|
14
|
|
Sum
|
8
|
2
|
3
|
8
|
4
|
8
|
0
|
0
|
2
|
2
|
6
|
4
|
1
|
6
|
5
|
X
|
·
Sum up the products,
Sum =
8+2+3+8+4+8+0+0+2+2+6+4+1+6+5 = 59
|
·
Subtract the unit digit from 10,