# Do payload field names require camelCase?

Source: https://developer.avalara.com/products/avalara-1099-and-w9/integration-guides/1099-and-w-9/ixy6622722864619/

Guide: 1099 & W-9

# Do payload field names require camelCase?

Learn if camelCase is mandatory for API payload field names.

Yes. The API expects all request payloads to use camelCase. Using capitalized keys results in validation failures.