Invoice Management System with Gmail Reminders, Google Sheets, and Slack Escalations — n8n Workflow

High complexity🔗 Webhook22 nodes🏷️ Invoice Processingby 飯盛　正幹

Overview

Who is this for?

This template is designed for freelancers, small businesses, and finance teams who need automated invoice management with intelligent payment follow-ups. Perfect for service providers, agencies, or any business that needs to track receivables and reduce late payments.

What this workflow does

This workflow provides complete invoice lifecycle management with two main flows:

Invoice Generation Flow: Receives order data via webhook with line items Splits line items using Split O

Nodes used

Google SheetsSlackGmailCode

Workflow Preview

Generate invoices and send payment reminders
Who is this for?
Freelancers, small businesses, and finance teams who ne
Step 1: Invoice Creation
Receive order data, generate invoice ID, and initialize
Step 2: Line Item Processing
Split Out each line item, calculate totals, and Aggrega
Step 3: Daily Overdue Check
Schedule Trigger runs daily. Loop Over batches each inv
Step 4: Reminder Escalation
Switch routes to 5 reminder levels based on days overdu
⚡
N
New Invoice Request
I
Initialize Invoice
S
Split Line Items
Calculate Line Total
A
Aggregate Line Items
Build Invoice Object
Save Invoice to Sheet
Send Invoice Email
⚡
I
Invoice Created Response
⚡
D
Daily Overdue Check
Get Unpaid Invoices
Calculate Overdue Days
L
Loop Over Invoices
R
Route by Reminder Level
First Reminder Email
Second Reminder Email
Urgent Reminder Email
Final Notice Email
Escalate to Collections
M
Merge Reminder Paths
Update Reminder Date
Continue Loop
22 nodes25 edges

How it Works

  1. 1

    Trigger

    The workflow starts with a webhook trigger.

  2. 2

    Process

    Data flows through 22 nodes, connecting aggregate, code, gmail.

  3. 3

    Output

    The workflow completes its automation and delivers the result to the configured destination.

Node Details (22)

GO

Google Sheets

googleSheets

#1
SL

Slack

slack

#2
GM

Gmail

gmail

#3
CO

Code

code

#4

How to Import This Workflow

  1. 1Click Download JSON button on the right to save the workflow file.
  2. 2Open your n8n instance. Go to Workflows → New → Import from file.
  3. 3Select the downloaded invoice-management-system-with-gmail-reminders-google-sheets-and-slack-escalations file and click Import.
  4. 4Set up credentials for each service node (API keys, OAuth, etc.).
  5. 5Click Test Workflow to verify everything works, then activate it.

Or paste directly in n8n → Import from JSON:

{ "name": "Invoice Management System with Gmail Reminders, Google Sheets, and Slack Escalations", "nodes": [...], ...}

Integrations

aggregatecodegmailgooglesheetsmergerespondtowebhookscheduletriggersetslacksplitinbatchessplitoutswitchwebhook

Get This Workflow

Download and import in one click

Download JSONView on n8n.io
Nodes22
Complexityhigh
Triggerwebhook
CategoryInvoice Processing

Created by

飯盛　正幹

飯盛　正幹

@isakai

Tags

aggregatecodegmailgooglesheetsmergerespondtowebhookscheduletriggersetslacksplitinbatches
⚡

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Automate Custom QuickBooks Invoice PDFs & Email with n8n

Standard accounting templates often fail to reflect a premium brand identity. This sophisticated n8n workflow bridges the gap between financial record-keeping and professional client presentation. By moving beyond the native limitations of QuickBooks Online, this automation enables businesses to generate high-end, multi-page PDF invoices that align perfectly with their corporate styling. The process begins the moment a new invoice is generated in QuickBooks, triggering a webhook that captures real-time billing data. The workflow then utilizes advanced HTML-to-File conversion and custom Code nodes to structure data into a polished, branded layout. It handles complex logic such as line-item merging and multi-page formatting automatically. Once the document is rendered, the system bypasses generic 'no-reply' senders by routing the finalized PDF through your preferred email provider. This ensures a seamless, white-labeled experience for your clients while eliminating the manual overhead of exporting, styling, and attaching files. Ideal for agencies and service providers, this flow guarantees that your most frequent touchpoint—the bill—is as professional as your work. **Common Use Cases:** - High-end creative agencies requiring bespoke, white-labeled billing documents for premium clients. - Automated recurring subscription billing where custom tax disclosures or localized branding are required. - Service-based businesses needing to attach dynamic project reports or terms of service directly to QuickBooks invoices.

🔗 Webhook·12 nodes