> For the complete documentation index, see [llms.txt](https://docs.verygoodsecurity.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verygoodsecurity.com/cmp/products-and-services/payment-account-reference-par.md).
# Payment Account Reference (PAR)
### Overview
The VGS Payment Account Reference (PAR) Service API links a cardholder’s Primary Account Number (PAN) or Network Token to its corresponding Payment Account Reference (PAR) value. Designed as an intermediary between our clients and the major card networks, this service addresses the core tracking challenges introduced by widespread card tokenization.
By utilizing this API, clients can seamlessly retrieve the PAR value for any vaulted card. The service abstracts the operational complexities typically associated with direct network integrations, including managing disparate multi-network APIs, varying encryption schemes, and secure credential management.
Ultimately, the PAR value allows merchants and platforms to link tokenized and PAN-based transactions back to the same unique account without exposing or storing the sensitive PAN itself. This document serves as the primary reference guide for development and integration.
The Payment Account Reference (PAR) is an uppercase, alphanumeric string ranging from 29 to 32 characters in length, most commonly 29 characters for networks like Mastercard and Discover, and up to 32 characters for Visa. The first 4 characters represent the network's BIN Controller Identifier (e.g., Mastercard: `5001`, Visa: `4001`) to specify the issuing card brand, while the remaining characters form a unique, pseudo-random value generated by that network to permanently identify the underlying payment account.
### Benefits of the VGS PAR Service
Because PAR is constant across a card's tokens, channels, and lifecycle events, it connects activity that would otherwise look like separate customers:
* **Loyalty & rewards:** Identify customers and apply points to the correct account, even when they pay with different tokens.
* **Omnichannel:** Link a customer across online, in-store, and mobile so one profile follows them everywhere.
* **Subscriptions:** Tie recurring billing to one account and prevent free-trial abuse across tokens.
* **Returns:** Match a purchase made with one token to a return made with another.
* **Fraud prevention:** Answer "Have we seen this credential before?" and connect risk signals across credentials
### How the VGS PAR Service works
The VGS PAR Service serves as an intermediary between you and the 4 major card networks, providing a single, clean integration rather than multiple ones. Retrieving a PAR value takes a single call against a card that is already vaulted with VGS:
1. Initiate the request. Call the PAR endpoint using the `card_id` of a card already securely vaulted with VGS.
2. Determine the lookup method. The service uses the token\_type on the card object to pick the correct lookup credential. Each value maps to a distinct credential type: `pan` (the underlying card number), `dpan` (a device-provisioned token, e.g., from a wallet like Apple Pay or Google Pay), and `network_token` (a network-issued card-on-file token).
3. Call the network. The endpoint always triggers a live network call with the appropriate credentials.
4. Persist and return. On a successful response, VGS persists the PAR onto the card object for future use and returns the PAR payload to you.
Behind that single endpoint, VGS abstracts away the operational complexity that usually comes with direct network integrations: disparate multi-network APIs, varying encryption schemes, and secure credential management.
### Built into the Card Management Platform
You can adopt PAR as a standalone service or as an integrated capability within the [VGS Card Management Platform](https://www.verygoodsecurity.com/card-management-platform). Either way, VGS is ready to help you simplify payment account identification at scale and pass PAR back to you from supporting acquirers, including [Apple Pay](https://www.apple.com/apple-pay/).
### Onboarding
**Account Setup & Prerequisites:** Before merchants can use the PAR service, their account must be configured.
1. **Enable PAR on Your Account:** PAR must be explicitly enabled for your VGS account. Please contact or merchant-designated VGS implementation representative to have this feature activated.
2. **Configure Service Account:** Once PAR is enabled, merchants should configure their Service Account with the necessary permissions, including the `account-reference-numbers:read` scope (in addition to `cards:read` and `cards:write`).
3. Create Card IDs using stored PANs.
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