You’ll need to follow Mastercard’s validation requirements for the merchant city name field if you pass us your city name dynamically using the billing_descriptor.city field.
To ensure you’re compliant under their data integrity monitoring program, please ensure the city name does not include any special characters (underscores, hyphens, commas, etc.)
For transactions in the United States, you should also ensure that you update your dynamic billing descriptor before June 30, 2026 to ensure that:
- The city name is not a blank or dummy value (all spaces, all numeric, or null)
- The city is a valid city, corresponding to the relevant ZIP code
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