topic Re: Amex last four numbers. in Credit Cards

Amex last four numbers.

ilovelisa — Thu, 28 Aug 2014 11:51:37 GMT

So at where I work, I am exposed to many American Express cards and account numbers. Even after the swipe, I have to type in the last four embossed numbers for verification. They are usually always the same. The last four are usually 1003, 1007, 1008, 1013, etc. So does anybody know if this means anything? Is it just by card type? I received an email about my card and the last four are 1007. So these numbers are obviously not part of the actual account number because everybody would have the same ending numbers. So anybody know what they mean?

Re: Amex last four numbers.

EvilR-T — Thu, 28 Aug 2014 12:00:51 GMT

my last four start with a 2

Re: Amex last four numbers.

nmac — Thu, 28 Aug 2014 12:34:17 GMT

@ilovelisa wrote:
So at where I work, I am exposed to many American Express cards and account numbers. Even after the swipe, I have to type in the last four embossed numbers for verification. They are usually always the same. The last four are usually 1003, 1007, 1008, 1013, etc. So does anybody know if this means anything? Is it just by card type? I received an email about my card and the last four are 1007. So these numbers are obviously not part of the actual account number because everybody would have the same ending numbers. So anybody know what they mean?

I don't know that it means anything but I find it annoying. My PRG before it was canceled had the same last 4 as my EDP. This made it impossible to know what amex card was saved online or to know what I card I paid with when looking a a receipt.

Re: Amex last four numbers.

AirlinerDudeB6 — Thu, 28 Aug 2014 12:36:04 GMT

@ilovelisa wrote:
So at where I work, I am exposed to many American Express cards and account numbers. Even after the swipe, I have to type in the last four embossed numbers for verification. They are usually always the same. The last four are usually 1003, 1007, 1008, 1013, etc. So does anybody know if this means anything? Is it just by card type? I received an email about my card and the last four are 1007. So these numbers are obviously not part of the actual account number because everybody would have the same ending numbers. So anybody know what they mean?

AMEX card nubmers follow this format:

3XXX XXXXXX XABBC

A = card sequence number (starts with 1 and will increase by 1 each time a new account number is issued, usually due to theft or lost card)

BB = "00" for first primary card on the account. "01" for first supplementary card..."02" for the second...and so on...

C = Check digit - determined using LUHN formula (google if you are bored and enjoy math)

In your case of 1007 = this is the first account number issued on this card, it is the primary card, and your check digit is 7.

The reason some merchant POS systems require the last 4 digits to be entered, is so the system can validate the "check digit" as an extra layer of fraud protection.

Re: Amex last four numbers.

ilovelisa — Thu, 28 Aug 2014 15:15:08 GMT

@AirlinerDudeB6 wrote:
@ilovelisa wrote:
So at where I work, I am exposed to many American Express cards and account numbers. Even after the swipe, I have to type in the last four embossed numbers for verification. They are usually always the same. The last four are usually 1003, 1007, 1008, 1013, etc. So does anybody know if this means anything? Is it just by card type? I received an email about my card and the last four are 1007. So these numbers are obviously not part of the actual account number because everybody would have the same ending numbers. So anybody know what they mean?

AMEX card nubmers follow this format:

3XXX XXXXXX XABBC

A = card sequence number (starts with 1 and will increase by 1 each time a new account number is issued, usually due to theft or lost card)

BB = "00" for first primary card on the account. "01" for first supplementary card..."02" for the second...and so on...

C = Check digit - determined using LUHN formula (google if you are bored and enjoy math)

In your case of 1007 = this is the first account number issued on this card, it is the primary card, and your check digit is 7.

The reason some merchant POS systems require the last 4 digits to be entered, is so the system can validate the "check digit" as an extra layer of fraud protection.

Thanks for your reply. I knew they all had to mean something about the account since I've seen so many with the same numbers.

Re: Amex last four numbers.

afinch1992 — Thu, 28 Aug 2014 18:32:12 GMT

Wow, interesting info. Thank you for the insight!

Re: Amex last four numbers.

trumpet-205 — Thu, 28 Aug 2014 18:42:25 GMT

I once made a large purchase at Walmart and the terminal asked me to type in the 3 digits on the signature panel (not 4 digits CVV at the front).

Note that the number scheme AirlinerDudeB6 explained only works for AMEX issued card. My Fidelity AMEX does NOT follow such number scheme.