Where should I set my company's UIC (Unique Identifier)

Hello, I want my purchases from Envato to be a business expense. I understand that in order to edit my billing information, I need to re-submit my tax information. There is a field for the “Tax ID Type” with options:

  • U.S. Social Security Number (SSN)
  • U.S. Employer Identification Number (EIN)
  • Individual Taxpayer Identification Number (ITIN)
  • Foreign Tax ID Number
  • I will not or am unable to provide a Tax ID Number

( See the screenshot: Screenshot by Lightshot )

There is a “Company No.” field at the bottom of the billing information ( See the screenshot: Screenshot by Lightshot ). In which of the two places - “Foreign Tax ID” or “Company No.” should I enter UIC (Unique identifier)?

My company is not registered for VAT.

Thank you.