I understand that this number relates to the country the card is issued in.
It is used by benefit providers (such as airline lounges) to determine whether you are entitled to the benefit. For example, the UK card may allow you access to a particular airline lounge... they can restrict it to UK issued cards with reference to the four digit number.
I was told this a long time ago by AMEX when I asked.
They are generally put on charge cards... but not credit cards.
I have 5007 on my Platinum Charge Card... and always have.
It is used by benefit providers (such as airline lounges) to determine whether you are entitled to the benefit. For example, the UK card may allow you access to a particular airline lounge... they can restrict it to UK issued cards with reference to the four digit number.
I was told this a long time ago by AMEX when I asked.
They are generally put on charge cards... but not credit cards.
I have 5007 on my Platinum Charge Card... and always have.