Invoice creator with Google Sheets & automated email payment reminder system

This automated n8n workflow streamlines invoice creation and payment reminders. It generates invoices on a monthly schedule and sends reminders for overdue payments, updating records in Google Sheets.

Good to Know - Supports monthly invoice generation and daily overdue checks - Integrates with Google Sheets for data management - Uses email notifications for invoice delivery and reminders - Includes logging for tracking and auditing - Features multiple reminder types based on overdue duration

How It Works Invoice Creation Flow: - Monthly Invoice Trigger - Initiates workflow on a set monthly schedule - Get Clients for Invoicing - Reads client data from Google Sheet - Filter Active Clients - Filters out inactive clients - Generate Invoice Data - Creates invoice details in required format - Save Invoice to Google Sheets - Appends or updates invoice record in the sheet - Send Invoice Email - Sends the invoice to the client via email - Log Invoice Creation - Logs invoice creation for records/auditing

Reminder Flow: - Daily Payment Reminder Check - Triggers workflow daily to check overdue invoices - Get Overdue Invoices - Reads overdue invoices from Google Sheet - Filter Overdue Invoices - Filters invoices still unpaid - Calculate Reminder Type - Calculates how many days overdue - Switch Reminder Type - Decides which type of reminder to send - Send Gentle / Follow-up / Urgent / Final Notice - Sends respective reminder email - Update Reminder Log - Updates reminder status in the sheet

How to Use - Import workflow into n8n - Configure Google Sheets API for data access - Set up email service for notifications - Define monthly schedule for invoice trigger - Test with sample client data and monitor reminders - Adjust reminder thresholds as needed

Requirements - Access to Google Sheets API - Email service configuration - Scheduled trigger setup in n8n

Sheet Columns: - Client Name - Invoice ID - Amount - Due Date - Status - Reminder Type - Last Updated

Customizing This Workflow - Modify invoice generation schedule - Adjust reminder email templates - Configure custom Google Sheet columns - Set custom overdue thresholds - Integrate additional notification methods