{"product_id":"n8n-google-calendar-to-invoice-automation-docs-gmail-sheets","title":"n8n Google Calendar to Invoice Automation (Docs, Gmail, Sheets)","description":"\u003ch3\u003eTurn monthly Google Calendar time into ready-to-send client invoices—automatically\u003c\/h3\u003e\n\u003cp\u003eThis n8n workflow automatically converts tagged Google Calendar events from the previous month into draft invoices, emails them to you for approval via Gmail, generates a Google Docs PDF invoice, emails it to your client, and logs everything in Google Sheets—so you never double-bill or manually reconcile timesheets again.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cb\u003eRuns monthly\u003c\/b\u003e at 07:00 on the 1st and sets the billing period to the \u003cb\u003eprevious calendar month\u003c\/b\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eLoads billing data\u003c\/b\u003e from Google Sheets: client details, tags, hourly rates, currency, and tax rate %, plus invoice\/billing logs to prevent duplicates.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eFetches last month’s events\u003c\/b\u003e from Google Calendar and parses event titles to find \u003cb\u003eclient tags in square brackets\u003c\/b\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eFilters events\u003c\/b\u003e: skips cancelled, all-day, declined, and already-billed events.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eCalculates invoice totals\u003c\/b\u003e: rounds billable time to your defined increment, applies hourly rates, and calculates totals \u003cb\u003eincluding tax\u003c\/b\u003e using the rates stored in Google Sheets.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eCreates draft invoices\u003c\/b\u003e and sends each draft to you via \u003cb\u003eGmail\u003c\/b\u003e for approval (waits for approval or rejection).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eGenerates and sends final invoices\u003c\/b\u003e: for approved drafts, copies a Google Docs invoice template in Google Drive, fills placeholders, exports to \u003cb\u003ePDF\u003c\/b\u003e, then emails the PDF to the client via Gmail.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eLogs outcomes\u003c\/b\u003e by appending sent invoice details to an \u003cb\u003eInvoices\u003c\/b\u003e sheet and writing each billed event to a \u003cb\u003eBilling log\u003c\/b\u003e sheet.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eFreelancers billing clients by hours tracked in Google Calendar.\u003c\/li\u003e\n  \u003cli\u003eAgencies that need monthly invoices with tax based on client-specific rates.\u003c\/li\u003e\n  \u003cli\u003eSaaS operators using n8n to streamline invoice processing without building a full billing system.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cb\u003eSchedule:\u003c\/b\u003e 07:00 on the 1st of every month\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eIntegrations\/nodes:\u003c\/b\u003e if, code, no op, Gmail, Google Docs, Google Calendar, Google Sheets, Google Drive (template copy + PDF export)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cb\u003eRequired setup:\u003c\/b\u003e a Google Sheets file with a \u003cb\u003eClients\u003c\/b\u003e tab (Tag, Client, Email, Hourly rate, Currency, Tax rate %) plus sheets for invoice and billing logging.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":46146304901299,"sku":"N8N-20254","price":13.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/OEzhy3VZQksK_FvfvuJaY_BjYX6nMf.png?v=1790845857","url":"https:\/\/buyflowscripts.com\/products\/n8n-google-calendar-to-invoice-automation-docs-gmail-sheets","provider":"N8N Commerce","version":"1.0","type":"link"}