Supported Zip Code Formats

When submitting a customer via the POST /participants/customers/new endpoint, the Zero Hash API has the following validation logic on the zip field:

• Can either be 5 numbers (standard format) or 5 numbers, a hyphen, followed by 4 more numbers (Zip+4).
  • Standard: 12345
  • Zip+4: 12345-6789
• Avoid trailing whitespace, i.e. you should submit "12345" and not "12345 ".