From: Mark Day <mday@...>
Date: 2007-04-28T12:47:37+09:00
Subject: Re: [QUIZ] Checking Credit Cards (#122)

On Apr 27, 2007, at 8:39 PM, Raj Sahae wrote:

> Tim Becker wrote:
>>> For completeness and to make this Quiz exercise valid to more  
>>> people,
>>> can anyone include the information for other major credit cards from
>>> major countries? Japan: JCB,  et. al., U.K.: Barclay, et. al. ,  
>>> etc...
>>
>> UK had Switch and Solo till recently which are now rebranded under  
>> the
>> Maestro umbrella. They're not really credit cards and basically no
>> rules exist, you have to check tables to determine valid prefixes and
>> card number length. Additionally, Maestro card numbers may also be
>> Mastercard numbers, so they can't be uniquely identified as being
>> Maestro.
>>
>> For JCB and Diner's:
>>
>> JCB       3528-2589  Length: 16
>> Diners   3000-3029, 3040-3059, 36, 3815-3889, 389 Length: 14
>>
> There's no way to differentiate between a JCB starting with 34 and  
> an American Express card that starts with 34 given those starting  
> numbers.

Tim corrected his typo:

>> > JCB       3528-2589  Length: 16
>
> should be 3528-3589, obviously.

So I don't think a leading 34 is ambiguous.  It would be American  
Express, with an expected length of 15 digits.

-Mark