Zoho has free accounts and one of the available apps is invoicing. They have all the features you ask for. You can even integrate the &quot;here&#x27;s an invoice, pay me&quot; emails with payment processors. I&#x27;ve only used it for a few months, but can&#x27;t complain - it had way more features than I ever needed.<p><a href="https:&#x2F;&#x2F;www.zoho.com&#x2F;invoice&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.zoho.com&#x2F;invoice&#x2F;</a><p>(it&#x27;s a service, not opensource software though - I assume you really meant free <i>or</i> opensource)