---
title: externalIdentifier
framework: passkit
role: symbol
role_heading: Instance Property
path: passkit/pkpaymenttokencontext/externalidentifier
---

# externalIdentifier

An external identifier for the merchant.

## Declaration

```swift
var externalIdentifier: String { get set }
```

## Discussion

Discussion An external identifier for the merchant that the app developer provides. If you request a payment token for another merchant, always use the same external identifier for that merchant in your app.

## See Also

### Specifying the merchant

- [merchantIdentifier](passkit/pkpaymenttokencontext/merchantidentifier.md)
- [merchantDomain](passkit/pkpaymenttokencontext/merchantdomain.md)
- [merchantName](passkit/pkpaymenttokencontext/merchantname.md)