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from http://perl.about.com/compute/perl/library/nosearch/P073000.htm
verified by http://www.beachnet.com/~hstiles/cardtype.html
Card Type                         Prefix                           Length
MasterCard                        51-55                            16
VISA                              4                                13, 16
American Express (AMEX)           34, 37                           15
Diners Club/Carte Blanche         300-305, 36, 38                  14
enRoute                           2014, 2149                       15
Discover                          6011                             16
JCB                               3                                16
JCB                               2131, 1800                       15

--

from Neale Banks <neale@lowendale.com.au>
According to a booklet I have from Westpac (an Aussie bank), a card number
starting with 5610 or 56022[1-5] is a BankCard
BankCards have exactly 16 digits.

--

from "Becker, Max" <Max.Becker@firstgate.com>
It's mostly used in the UK and is either called "Switch" or "Solo".
Card Type                         Prefix                           Length
Switch                            various                          16,18,19
Solo                              63, 6767                         16,18,19

switch
4903
   0[2-9]
   3[5-9]
4911 
   0[1-2]
   7[4-9]
   8[1-2]
4936

--

from http://en.wikipedia.org/wiki/Credit_card_number#Prefixes
As of November 8, 2004, MasterCard and Diner's club formed an alliance.
Cards issued in Canada and the USA start with 55 and are treated as
MasterCards worldwide. International cards use the 36 prefix and are
treated as mastercards in Canada and the US, but are treated as Diner's
Club cards elsewhere. Diner's club international's website makes no
reference to old 38 prefix numbers, and they can be presumed reissued under
the 55 or 36 BIN prefix.

Effective October 1, 2006, the Discover Network will activate new Issuer
Identification Numbers (IINs) to support a variety of card types and
products. Additionally, Discover and China Union Pay (CUP) have
established a strategic alliance and reciprocity agreement. As a result,
IIN ranges from CUP will be enabled to facilitate the acceptance of CUP
credit Cards on the Discover Network by October 1, 2006. CUP credit
cards will be enabled on Discover Network with a 16-digit Card Number
only. The updated IIN table is shown below.

Minimum IIN             Maximum IIN             Product
650000          650099          Consumer Debit
650100          650199          Commercial Debit
650200          650399          Stored Value
650400          650599          Stored Value
650600          650799          Consumer Credit
650800          650999          Commercial Credit
651000          659999          Reserved for Future Use

        China Union Pay
62212600                62292599                Credit

Please ensure that your POS terminals, websites and any pertinent
internal systems can accept these new IINs.

--

from http://en.wikipedia.org/wiki/Laser_(debit_card)#Technical
Laser cards are prefixed with either "6304", "6706", "6771" or "6709", and
may be between 16 and 19 characters in length.

--

from https://www.discovernetworkvar.com/pdf_docs/9-2_VAR_ALERT_Sep_2009.pdf
Be sure to update your POS systems now with the following expanded Issuer
Identification Number ("IIN") Ranges.  The IIN Range table listed below
includes Diners Club International ("DCI") and other Issuers and Card
programs that operate on Discover Network. These ranges are required for Card
transaction routing and detailed in Release 9.2 of the Discover® Network
Acquirer Operating Regulations and Technical Specifications:

                     Start              End                 Issuing
                                                            Network
                     30000000           30599999            DCI
                     30950000           30959999            DCI
                     35280000           358999991           JCB
                     36000000           369999992           DCI
                     38000000           39999999            DCI
                     60110000           60110999            Discover
                                                            Network
                     60112000           60114999            Discover
                                                            Network
                     60117400           60117499            Discover
                                                            Network
                     60117700           60117999            Discover
                                                            Network
                     60118600           60119999            Discover
                                                            Network
                     62212600           62292599            CUP
                     62400000           62699999            CUP
                     62820000           62889999            CUP
                     64400000           65999999            Discover
                                                            Network

1 This IIN range (35280000 to 35899999) shall be enabled only by Merchant
Processors in connection with Merchant relationships, POS Devices or otherw
of the United States of America and the District of Columbia, Puerto Rico, th
Northern Mariana Islands and Guam, subject to certain exceptions in Acquir
applicable.
2 The PAN length for this IIN Range (36000000 to 36999999) is 14 digits.

--

from SBH Israel / Nir Alfandari:
Local Isracard: 8(-9?) digits

From http://www.wysiwyg.co.il/Anatomy-of-CreditCard-Number-formats.asp#IsraCard-algorithm
8-9 digits, non-LUHN validation

From Erik Levinse:
 i think it's like luhn, except instead of 212121... you put
+987654321 under the number you're validating, multiply each, and do mod 11 on
+the sum, instead of mod 10.


--------------------

From Jason Terry:

 list of the IIN values that were given to us by Discover.  We manually tested a number from each end of the range to make sure B:CC worked.
 
 30000000-30599999 DCI
 30950000-30959999 DCI
 35280000-35899999 JCB * us only
 36000000-36999999 DCI * 14 digits
 38000000-39999999 DCI
 60110000-60110999 DN
 60112000-60114999 DN
 60117400-60117499 DN
 60117700-60117999 DN
 60118600-60119999 DN
 62212600-62292599 CUP
 62400000-62699999 CUP
 62820000-62889999 CUP
 64400000-65999999 DN

---

DCI = diner's, now discover everywhere
JCB = treat JCB as discover inside the US
DN = Discover Network
CUP = China Union Pay, treat as Discover outside China