Most free invoice tools want an email address before they will show you a document, watermark the PDF, or keep your customer list on someone else's server. InvoiceWorkshop does none of those. Open it, fill it in, download the PDF. It covers the paperwork a small business actually cycles through, invoices, quotations, estimates, work orders, purchase orders, proforma invoices, receipts, credit notes, timesheet invoices, delivery notes and construction progress draws, and moves between them: quote a job, turn the quotation into an invoice, receipt the payment when it lands, credit it if something comes back. Tax is computed per line and rounded there, with country presets for UK VAT, India GST, Australian tax invoices and Canadian GST/HST. Free, no signup, no upload, no watermark.
Generating an invoice should take a minute. In practice most free tools want an email address before they will show you a document, then watermark the PDF or keep your customer list on their server. I built InvoiceWorkshop to remove it: open it, fill it in, download a clean PDF. No signup, no upload, no watermark. It grew from invoices into the rest of the paperwork a small business cycles through because the same friction shows up on all of them.