Billy

About Billy

Billy is a free, open-source invoice editor that runs entirely in your browser. Open the editor and the invoice is already there: your details at the top, a first line item waiting. Click any line and type. There are no forms, no modals and no wizard, because you edit the invoice itself. Your draft saves automatically in your own browser, so you can close the tab and come back to it. When the invoice looks right, download the PDF. The export renders the exact page you were editing, so the PDF matches the screen: same layout, same line breaks, same page count, ready to send or print. It comes with ten templates (Clean, Modern Green, Minimal Teal, Corporate Blue, Mono Classic, Mono Elegant, Studio, Ledger, Receipt, Letterhead), ten currencies (INR, USD, EUR, GBP, JPY, AUD, CAD, SGD, AED, SAR), tax and discount, payment terms, bank details, PO numbers, notes and terms, plus logo and digital stamp upload. Invoices longer than one page paginate cleanly. For India there is full GST support: GSTIN, HSN and SAC codes, CGST, SGST, IGST and reverse charge, with presets for freelancers, GST vendors, agencies and consultants that turn on exactly the fields each one needs. Billy also works with AI assistants. It speaks MCP, so in ChatGPT, Claude or any MCP-compatible assistant you can describe the client and the job, and the assistant fills in the invoice and hands you a link that opens it in the editor, ready to adjust and export. The pairing page is at trybilly.tech/connect. What there is not: no account, no sign-up, no server, no database. Nothing you type is uploaded. The only outbound request the app makes is anonymous analytics. The code is on GitHub under the MIT license, free to read, self-host or change. Billy is for freelancers and one-person studios who send a few invoices a month and do not want to learn invoicing software to do it. It deliberately leaves accounting out: no expense tracking, no bank feeds, no bookkeeping, no tax filing, no client portal and no payment processing.

What people use it for

Write an invoice and download the PDF in a couple of minutes, with no sign-up. Describe the client and the job to an AI assistant and open the finished invoice from a link it gives you. Download a PDF that matches the editor exactly, page for page. Send invoices in ten currencies with tax, discounts, bank details and payment terms. Bill clients in India with GSTIN, HSN and SAC codes and CGST, SGST or IGST lines. Save your logo, digital stamp and business details once and reuse them on every invoice.

Tags

• #businesses
• #consultants
• #designers
• #freelancers
• #indie developers