Send overdue invoice reminders from Pennylane to Slack

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1. Workflow Overview

Who is this for Finance teams and freelancers using Pennylane (French accounting platform) who want daily alerts for unpaid invoices that need follow up. What it does This workflow runs daily at 9 ...

Best for

Invoice Processing automation workflows
intermediate n8n builders looking for reusable templates

Tools used

n8n-nodes-base.stickynote, n8n-nodes-base.scheduletrigger, n8n-nodes-base.httprequest, n8n-nodes-base.code, n8n-nodes-base.if, n8n-nodes-base.set, n8n-nodes-base.slack

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Gauthier Huguenin.

Original n8n.io source

1.1 Workflow description

Title: Send overdue invoice reminders from Pennylane to Slack
Workflow name: Send overdue invoice reminders from Pennylane to Slack

Who is this for

Finance teams and freelancers using Pennylane (French accounting platform) who want daily alerts for unpaid invoices that need follow-up.

What it does

This workflow runs daily at 9 AM, fetches all customer invoices from Pennylane, and identifies unpaid invoices past their deadline by 7 or more days. If overdue invoices are found, it sends a detailed Slack reminder with invoice number, amount, days overdue, and a direct link to the PDF. If no invoices are overdue, the workflow ends silently.

How to set up

Import this workflow into n8n
Create a Header Auth credential with name Authorization and value Bearer <YOUR_PENNYLANE_TOKEN>
Select your Slack channel in the SL Send Notification node
Adjust the schedule time in the Schedule Trigger node if needed

Requirements

Pennylane account with API access (Essentiel plan or higher)
Pennylane API token with scope: customer_invoices:all
(Optional) Slack workspace for notifications

How to customize

Change THRESHOLD_DAYS in the Code Filter Overdue node to adjust when reminders trigger (default: 7 days past deadline)
Change the schedule time in the Schedule Trigger node (default: 9 AM daily)
Replace Slack with Telegram, Email, or any other notification channel

Part of a 3-workflow billing automation suite: https://github.com/Gauthier-Huguenin/n8n-pennylane-auto-invoicing

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - Sticky Note

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 2 - Schedule Trigger

Type / Role: n8n-nodes-base.scheduleTrigger - scheduleTrigger
Config choices: Version 1.3

Block 3 - PL Fetch Invoices

Type / Role: n8n-nodes-base.httpRequest - httpRequest
Config choices: Version 4.4

Block 4 - Code Filter Overdue

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 5 - IF Has Overdue

Type / Role: n8n-nodes-base.if - if
Config choices: Version 2.3

Block 6 - Set Done

Type / Role: n8n-nodes-base.set - set
Config choices: Version 3.4

Block 7 - Code Build Reminder

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 8 - SL Send Notification

Type / Role: n8n-nodes-base.slack - slack
Config choices: Version 2.4

Block 9 - Sticky Note1

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 10 - Sticky Note2

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 11 - Sticky Note3

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 12 - Sticky Note4

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 13 - Sticky Note5

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

3. Summary Table

Workflow	Send overdue invoice reminders from Pennylane to Slack
Complexity	intermediate
Nodes	13
Categories	Invoice Processing
Author	Gauthier Huguenin
Published	21 Apr 2026

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/15189/15189.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source Invoice Processing workflows

Frequently asked questions

What does Send overdue invoice reminders from Pennylane to Slack do?

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your Invoice Processing use case.

Gauthier Huguenin

3 workflows

Nodes

n8n-nodes-base.stickynote n8n-nodes-base.scheduletrigger n8n-nodes-base.httprequest n8n-nodes-base.code n8n-nodes-base.if n8n-nodes-base.set n8n-nodes-base.slack

Complexity

intermediate

Published 21 Apr 2026

Likes 0

View on n8n.io Download Workflow

Install path: /data/workflows/15189/15189.json

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Send overdue invoice reminders from Pennylane to Slack

Workflow preview

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

Who is this for

What it does

How to set up

Requirements

How to customize

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Sticky Note

Block 2 - Schedule Trigger

Block 3 - PL Fetch Invoices

Block 4 - Code Filter Overdue

Block 5 - IF Has Overdue

Block 6 - Set Done

Block 7 - Code Build Reminder

Block 8 - SL Send Notification

Block 9 - Sticky Note1

Block 10 - Sticky Note2

Block 11 - Sticky Note3

Block 12 - Sticky Note4

Block 13 - Sticky Note5

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions