Business buyers need their tax ID on the invoice, but standard checkout has no field for it unless you are on Plus. Fiscal ID adds the field to the cart page, cart drawer, thank-you page and customer account. It validates as the buyer types: official check-digit rules for Spain, Argentina, Chile, Peru, Colombia and EU VAT, plus tax IDs for 80+ more countries (Brazil, Mexico, Italy, UK, US). Buyers can pick their country. Blocks checkout when required and saves the result on the order.

• Works on Basic, Shopify and Advanced plans. No Shopify Plus needed.
• Check-digit validation for ES, AR, CL, PE, CO, EU VAT and 80+ more countries.
• Require the ID always, only for invoices, or above an order amount.
• Saved to order and customer metafields any invoicing app can read.
• Orders missing a valid ID are tagged so you fix them before invoicing.