{"product_id":"automate-overdue-invoice-reminders-with-n8n-gemini-gmail-slack","title":"Automate Overdue Invoice Reminders with n8n, Gemini, Gmail \u0026 Slack","description":"\u003ch3\u003eAutomate Overdue Invoice Reminders with n8n, Gemini, Gmail \u0026amp; Slack\u003c\/h3\u003e\n\u003cp\u003eStop chasing overdue payments manually. This n8n workflow checks your \u003cstrong\u003eunpaid invoices in Google Sheets\u003c\/strong\u003e, uses \u003cstrong\u003eGoogle Gemini\u003c\/strong\u003e to draft stage-appropriate reminder emails, sends them via \u003cstrong\u003eGmail\u003c\/strong\u003e, optionally notifies \u003cstrong\u003eSlack\u003c\/strong\u003e for long-overdue cases, and updates the sheet so reminders continue correctly.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRuns daily at 09:00\u003c\/strong\u003e to keep reminders consistent.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReads invoice rows\u003c\/strong\u003e from the Google Sheets \u003cstrong\u003e“Invoices”\u003c\/strong\u003e sheet.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCalculates overdue status\u003c\/strong\u003e by computing how many days each invoice is overdue and how long it’s been since the \u003cstrong\u003eLast Reminder\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAssigns a reminder stage\u003c\/strong\u003e (gentle, firm, or escalate). If an invoice is not due or the last reminder was too recent, it skips sending.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGenerates the email body with Google Gemini\u003c\/strong\u003e, matching the tone to the selected stage, and sends via \u003cstrong\u003eGmail\u003c\/strong\u003e with a subject line tailored to that stage.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEscalates via Slack\u003c\/strong\u003e for “escalate” invoices: after sending the final notice, it posts an alert to your chosen \u003cstrong\u003e#finance\u003c\/strong\u003e channel.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUpdates Google Sheets\u003c\/strong\u003e with the latest reminder details (including a new reminder timestamp) so the sequence can continue on the next run.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eKeep SaaS billing teams focused by automating reminders for invoices that remain unpaid.\u003c\/li\u003e\n  \u003cli\u003eUse gentle-to-escalation messaging to reduce payment friction while still applying pressure over time.\u003c\/li\u003e\n  \u003cli\u003eEnsure finance visibility: automatically alert Slack when an invoice reaches the “escalate” stage.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003en8n schedule\u003c\/strong\u003e: daily at \u003cstrong\u003e09:00\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrations \/ nodes\u003c\/strong\u003e: Google Sheets, Google Gemini (PaLM) API, Gmail, Slack, plus workflow logic using Code, Switch, and Sticky Note nodes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRequired columns\u003c\/strong\u003e: Invoice No, Client, Contact Email, Amount, Due Date, Last Reminder (use consistent, parseable date formats)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":45822097162419,"sku":"N8N-18064","price":55.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/KC1klEZ6fg-8g5ClWVkQT_arsSZ2uu.png?v=1786526148","url":"https:\/\/buyflowscripts.com\/products\/automate-overdue-invoice-reminders-with-n8n-gemini-gmail-slack","provider":"N8N Commerce","version":"1.0","type":"link"}