| items | Yes | Line items, at least one, at most 200. Example: [{"description": "Design work", "quantity": 12, "unit": "hrs", "unit_price": 85}]. | |
| notes | No | Optional note printed at the bottom, e.g. 'Thank you for your business.' | |
| paper | No | PDF paper size. Defaults to letter for US/Canada locales and A4 elsewhere. | |
| client | No | Who receives the document: the client or customer. | |
| locale | No | Optional BCP 47 locale for number and date formats, e.g. en-US, en-GB, de-DE, pl-PL. Labels stay in English. Defaults to English for the currency's country. | |
| number | No | Document number exactly as it should appear, e.g. INV-0042. If omitted, one is derived from the issue date. | |
| seller | No | Who issues the document: the user's business or freelance name, address, email, optional tax ID. | |
| currency | No | ISO 4217 currency code, e.g. USD, EUR, GBP, PLN, JPY. Defaults to USD. Minor units follow ISO 4217 (JPY has none, KWD has 3). | |
| due_date | No | Payment due date (or valid-until date for quotes and estimates) as YYYY-MM-DD, e.g. 2026-10-16. | |
| shipping | No | Optional shipping or delivery charge, e.g. 15. | |
| reference | No | Optional purchase order or project reference, e.g. PO-7781. For credit notes, the original invoice number. | |
| tax_label | No | Name of the tax shown on the document, e.g. VAT, GST, Sales tax. Defaults to Tax. | |
| issue_date | No | Issue date as YYYY-MM-DD, e.g. 2026-10-02. Defaults to today (UTC). | |
| amount_paid | No | Amount already paid (deposit or partial payment), shown as a balance due, e.g. 500. Receipts default to the full total. | |
| accent_color | No | Optional brand accent colour as hex, e.g. #1D4ED8. Defaults to #0E7C66. | |
| document_type | No | Kind of document: invoice (default), quote, estimate, receipt (records a payment already received), or credit_note (refund or correction of an earlier invoice). | |
| amount_in_words | No | Set true to print the total in English words, e.g. 'One thousand twenty and 00/100 USD'. | |
| discount_amount | No | Optional fixed discount on the whole document before tax, e.g. 50. Use either this or discount_percent. | |
| discount_percent | No | Optional discount on the whole document in percent, applied to the subtotal before tax, e.g. 10. | |
| shipping_tax_rate | No | Tax rate in percent applied to shipping, e.g. 20. Defaults to 0 (shipping not taxed). | |
| payment_terms_days | No | Alternative to due_date: days after the issue date, e.g. 14 for 'Net 14' or 30 for 'Net 30'. 0 means due on receipt. | |
| payment_instructions | No | Optional free-text payment details from the user, e.g. bank name, IBAN, SWIFT, or a payment link. Never a card number. | |