How to generate a professional invoice PDF

1. Fill in seller and buyer blocks

   Required: "Business name" (seller) and "Client name" (buyer). Everything else — address, city, state, postal, country, email, phone, tax ID — is optional. Empty optional fields are omitted from the PDF.

2. Set invoice header

   "Invoice number" (required, alphanumeric/punctuation only — illegal characters are replaced with underscores in the filename). "Invoice date" required, "Due date" optional, both ISO YYYY-MM-DD. "Purchase order" optional.

3. Add line items and currency

   "Currency" picks an ISO 4217 code (USD default; only whitelisted codes pass validation). "Line items" — 1 to 50 rows with Description, Qty (>0), Unit price. Add rows in the visual line-item editor; quantity supports decimals.

4. Tax, terms, notes — then Run

   "Tax (%)" 0–100 (a single sales-tax-style rate applied to the subtotal). "Payment terms" and "Notes" are free text. Press Run for a PDF: result includes subtotal, taxAmount, total, formatted currency strings, and invoice-<number>.pdf filename.