What is an Issuer Identification Number?
An Issuer Identification Number (IIN) is the first eight digits of the long account number found on the front of a plastic card that complies with the international standard ISO/IEC 7812. This sequence of numbers, which can be up to a maximum of 19 digits, is called the Primary Account Number (PAN).
The purpose of the IIN is to identify the card issuer and inform acquirers and card issuers how to route a transaction. The IIN is used by financial institutions and other companies.
Additional information
In January 2017, ISO/IEC 7812 expanded from six digits to eight digits.
The PAN is composed of an issuer identification number (8 digits), individual account identification (maximum 12 digits) and an accompanying check digit (1 digit), calculated by the Luhn formula (see ISO 7812:2017). The maximum 19 digits include spaces used to separate the PAN for ease of visual reading as follows:

How to obtain an IIN
Pay.UK acts as an agent for the BSI (British Standards Institute) and is responsible for assigning UK National and International IINs on their behalf. Pay.UK also sponsors IINs for overseas countries that do not have their own sponsoring authority. We manage this process on behalf of ISO/IEC JTC1/SC17.
UK National IIN
For institutions based in the UK ONLY.
Cost: £350 + VAT (one off payment).
To apply for a UK National IIN, please download and complete the application and read the following documents. Please return the completed application to Standards-Card-Identifiers@wearepay.uk.
UK International IIN
For institutions based within the UK for cards designed for international acceptance.
Cost: £660 + VAT UK card issuers are also charged an annual maintenance fee of £30 + VAT starting on the first anniversary of the assignment.
To apply for a UK International IIN, please read the following important documents and download and complete the application form. Please return the completed application to Standards-Card-Identifiers@wearepay.uk.
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UK International IIN - Application form
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UK International IIN - Terms and conditions
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UK International IIN - Current ISO procedures as adopted for UK card issuers
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UK International IIN - How to differentiate between products
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UK International IIN - Using the 8 digit number to protect your business
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UK International IIN - Special information
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UK International IIN - Product pricing and payment methods
Overseas International IIN
Pay.UK assigns IINs to institutions based outside the UK that do not have a Sponsoring Authority. Applications will be sponsored by Pay.UK Limited on behalf of ISO/IEC JTC1/SC17.
Cost: £660 (one off payment) (VAT zero rated for countries outside the EU).
To apply for an Overseas IIN, please read the following important documents and download and complete the application form. Please return the completed application to Standards-Card-Identifiers@wearepay.uk.
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Overseas International IIN - Application form
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Overseas International IIN - Guidance for applicants
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Overseas International IIN - Using the 8 digit number to protect your business
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Overseas International IIN - How to differentiate between products
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Overseas International IIN - Special information
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Overseas International IIN - Product pricing and payment methods
Register of UK Card IINs
To obtain a copy of the Register of UK Card IINs (alpha and numerical) please download and complete the application. Please return the completed application to Standards-Card-Identifiers@wearepay.uk.
Cost: £100 + VAT