Gauthier Huguenin This workflow corresponds to n8n.io template #15189 — we link there as the canonical source.
This workflow follows the HTTP Request → Slack recipe pattern — see all workflows that pair these two integrations.
The workflow JSON
Copy or download the full n8n JSON below. Paste it into a new n8n workflow, add your credentials, activate. Full import guide →
{
"name": "Send overdue invoice reminders from Pennylane to Slack",
"nodes": [
{
"id": "7709720d-5bd0-419b-9a73-d63f4baf97fe",
"name": "Sticky Note",
"type": "n8n-nodes-base.stickyNote",
"position": [
-560,
-80
],
"parameters": {
"width": 528,
"height": 1088,
"content": "# Send overdue invoice reminders from Pennylane to Slack\n\n## Who is this for\n\nFinance teams and freelancers using Pennylane who want daily alerts for unpaid invoices that need follow-up.\n\n## What it does\n\nThis 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.\n\n## How to set up\n\n1. Import this workflow into n8n\n2. Create a Header Auth credential: name `Authorization`, value `Bearer <YOUR_PENNYLANE_TOKEN>`\n3. Select your Slack channel in the SL Send Notification node\n4. Adjust the schedule time in the Schedule Trigger node if needed\n5. Change THRESHOLD_DAYS in the Code Filter Overdue node to adjust sensitivity (default: 7 days)\n\n## Requirements\n\n- Pennylane account with API access (Essentiel plan or higher)\n- Pennylane API token with scope: customer_invoices:all\n- (Optional) Slack workspace\n\nPart of a 3-workflow billing suite: https://github.com/Gauthier-Huguenin/n8n-pennylane-auto-invoicing\n\n---\n\n### Flow\n\n`Schedule Trigger`\n \u2192 `PL Fetch Invoices`\n \u2192 `Code Filter Overdue`\n \u2192 `IF Has Overdue`\n \u2192 \u2705 `Code Build Reminder` \u2192 `SL Send Notification`\n \u2192 \u274c `Set Done`\n\n---\n\n### Node refs for $()\n\n- Schedule Trigger\n- PL Fetch Invoices\n- Code Filter Overdue\n- IF Has Overdue\n- Code Build Reminder\n- SL Send Notification\n- Set Done"
},
"typeVersion": 1
},
{
"id": "7c7a9506-5ec1-460d-a014-7d6db37c3a35",
"name": "Schedule Trigger",
"type": "n8n-nodes-base.scheduleTrigger",
"position": [
80,
224
],
"parameters": {
"rule": {
"interval": [
{
"triggerAtHour": 9
}
]
}
},
"typeVersion": 1.3
},
{
"id": "bf00125c-bc60-4c7e-8649-bf3d9faa2f42",
"name": "PL Fetch Invoices",
"type": "n8n-nodes-base.httpRequest",
"position": [
320,
224
],
"parameters": {
"url": "https://app.pennylane.com/api/external/v2/customer_invoices",
"options": {},
"authentication": "genericCredentialType",
"genericAuthType": "httpHeaderAuth"
},
"credentials": {
"httpHeaderAuth": {
"name": "<your credential>"
}
},
"typeVersion": 4.4
},
{
"id": "d25af660-3af7-4869-b149-7b9909ffbc0f",
"name": "Code Filter Overdue",
"type": "n8n-nodes-base.code",
"position": [
560,
224
],
"parameters": {
"jsCode": "// Refs: 'PL Fetch Invoices'\nconst invoices = $input.first().json.items;\nconst today = new Date().toISOString().split('T')[0];\nconst THRESHOLD_DAYS = 7;\n\nconst overdue = [];\n\nfor (const inv of invoices) {\n if (inv.draft || inv.paid) continue;\n if (inv.deadline >= today) continue;\n\n const deadlineDate = new Date(inv.deadline);\n const todayDate = new Date(today);\n const daysOverdue = Math.floor((todayDate - deadlineDate) / (1000 * 60 * 60 * 24));\n\n if (daysOverdue >= THRESHOLD_DAYS) {\n overdue.push({\n id: inv.id,\n invoice_number: inv.invoice_number,\n label: inv.label,\n currency_amount: inv.currency_amount,\n currency: inv.currency,\n deadline: inv.deadline,\n days_overdue: daysOverdue,\n customer_id: inv.customer.id,\n public_file_url: inv.public_file_url\n });\n }\n}\n\nreturn [{\n json: {\n overdue_count: overdue.length,\n overdue,\n has_overdue: overdue.length > 0\n }\n}];"
},
"typeVersion": 2
},
{
"id": "28c82e3c-1d77-4137-8396-3d79ef392cd8",
"name": "IF Has Overdue",
"type": "n8n-nodes-base.if",
"position": [
736,
224
],
"parameters": {
"options": {},
"conditions": {
"options": {
"version": 3,
"leftValue": "",
"caseSensitive": true,
"typeValidation": "strict"
},
"combinator": "and",
"conditions": [
{
"id": "1a032dfe-0694-4d96-8c75-c891a86339b2",
"operator": {
"type": "boolean",
"operation": "true",
"singleValue": true
},
"leftValue": "={{ $json.has_overdue }}",
"rightValue": ""
}
]
}
},
"typeVersion": 2.3
},
{
"id": "00fca357-c089-4a78-a7eb-9bbf9a1f76b9",
"name": "Set Done",
"type": "n8n-nodes-base.set",
"position": [
1552,
240
],
"parameters": {
"options": {},
"assignments": {
"assignments": [
{
"id": "7c77345e-ab79-4816-aa14-d62c9e9b61a9",
"name": "status",
"type": "string",
"value": "no overdue invoices"
}
]
}
},
"typeVersion": 3.4
},
{
"id": "73f0f390-b353-487b-ad7e-98a87ca7d4ca",
"name": "Code Build Reminder",
"type": "n8n-nodes-base.code",
"position": [
976,
144
],
"parameters": {
"jsCode": "// Refs: 'Code Filter Overdue'\nconst data = $input.first().json;\nconst lines = ['\ud83d\udea8 Overdue Invoice Reminder', ''];\n\nlines.push(`${data.overdue_count} invoice(s) require attention:`);\nlines.push('');\n\nfor (const inv of data.overdue) {\n lines.push(`\u2022 ${inv.invoice_number} | ${inv.currency_amount} ${inv.currency}`);\n lines.push(` Due: ${inv.deadline} (${inv.days_overdue} days overdue)`);\n lines.push(` ${inv.public_file_url}`);\n lines.push('');\n}\n\nreturn [{\n json: {\n message: lines.join('\\n'),\n overdue_count: data.overdue_count\n }\n}];"
},
"typeVersion": 2
},
{
"id": "04edc672-c812-4b77-8643-d68f58bbc2c1",
"name": "SL Send Notification",
"type": "n8n-nodes-base.slack",
"position": [
1168,
144
],
"parameters": {
"text": "={{ $json.message }}",
"select": "channel",
"channelId": {
"__rl": true,
"mode": "list",
"value": "",
"cachedResultName": ""
},
"otherOptions": {},
"authentication": "oAuth2"
},
"credentials": {
"slackOAuth2Api": {
"name": "<your credential>"
}
},
"typeVersion": 2.4
},
{
"id": "4ca9d854-033b-49bf-bd18-7fac67c6e674",
"name": "Sticky Note1",
"type": "n8n-nodes-base.stickyNote",
"position": [
16,
-80
],
"parameters": {
"color": 5,
"height": 480,
"content": "## 1. Trigger\n\nRuns once daily at 9:00 AM.\nChecks for overdue invoices that need\nfollow-up.\n\nAdjust schedule in the Schedule Trigger\nnode to fit your needs."
},
"typeVersion": 1
},
{
"id": "000b18e0-894f-4d7a-aeaa-efd9b9106545",
"name": "Sticky Note2",
"type": "n8n-nodes-base.stickyNote",
"position": [
256,
-80
],
"parameters": {
"color": 3,
"height": 480,
"content": "## 2. Fetch invoices\n\nRetrieves all customer invoices from Pennylane.\n\nEndpoint: GET /customer_invoices\n\nSame approach as WF2: no server-side\nstatus filtering available, all logic\nis handled in the Code node."
},
"typeVersion": 1
},
{
"id": "ba078fad-ae3c-4ebb-b045-384adf189fa5",
"name": "Sticky Note3",
"type": "n8n-nodes-base.stickyNote",
"position": [
496,
-80
],
"parameters": {
"color": 3,
"width": 432,
"height": 480,
"content": "## 3. Filter overdue\n\nIdentifies unpaid invoices past their\ndeadline by at least 7 days (THRESHOLD_DAYS).\n\nAdjust the threshold in Code Filter Overdue\nto change the sensitivity.\n\nSkips draft and paid invoices.\nCalculates exact days overdue for each."
},
"typeVersion": 1
},
{
"id": "c4d123ec-9c7d-41de-b22a-e93380e7e64a",
"name": "Sticky Note4",
"type": "n8n-nodes-base.stickyNote",
"position": [
928,
-80
],
"parameters": {
"color": 4,
"width": 480,
"height": 480,
"content": "## 4. Notify\n\nBuilds a detailed reminder with:\n- Invoice number and amount\n- Due date and days overdue\n- Direct link to the invoice PDF\n\nSends to Slack. Replace with your preferred\nnotification channel (Telegram, Email, etc.)."
},
"typeVersion": 1
},
{
"id": "a8a9b804-edbb-4123-beec-1f937e50eee6",
"name": "Sticky Note5",
"type": "n8n-nodes-base.stickyNote",
"position": [
1408,
-80
],
"parameters": {
"color": 4,
"width": 368,
"height": 480,
"content": "## 5. Done\n\nNo overdue invoices detected.\nWorkflow ends silently.\n\nThis node ensures a clean execution log\nin n8n. No notification is sent."
},
"typeVersion": 1
}
],
"active": false,
"settings": {
"binaryMode": "separate",
"callerPolicy": "workflowsFromSameOwner",
"timeSavedMode": "fixed",
"availableInMCP": true,
"executionOrder": "v1"
},
"connections": {
"IF Has Overdue": {
"main": [
[
{
"node": "Code Build Reminder",
"type": "main",
"index": 0
}
],
[
{
"node": "Set Done",
"type": "main",
"index": 0
}
]
]
},
"Schedule Trigger": {
"main": [
[
{
"node": "PL Fetch Invoices",
"type": "main",
"index": 0
}
]
]
},
"PL Fetch Invoices": {
"main": [
[
{
"node": "Code Filter Overdue",
"type": "main",
"index": 0
}
]
]
},
"Code Build Reminder": {
"main": [
[
{
"node": "SL Send Notification",
"type": "main",
"index": 0
}
]
]
},
"Code Filter Overdue": {
"main": [
[
{
"node": "IF Has Overdue",
"type": "main",
"index": 0
}
]
]
}
}
}
Credentials you'll need
Each integration node will prompt for credentials when you import. We strip credential IDs before publishing — you'll add your own.
httpHeaderAuthslackOAuth2Api
Pro
For the full experience including quality scoring and batch install features for each workflow upgrade to Pro
About this workflow
Finance teams and freelancers using Pennylane (French accounting platform) who want daily alerts for unpaid invoices that need follow-up.
Source: https://n8n.io/workflows/15189/ — original creator credit. Request a take-down →
Related workflows
Workflows that share integrations, category, or trigger type with this one. All free to copy and import.
This workflow is an automated employee time tracking and reporting system that monitors weekly work hours via TMetric, then delivers personalized summaries directly to each team member on Slack. It co
HTTP Request, Item Lists, Data Table +1
Import Productboard Notes Companies And Features Into Snowflake. Uses stickyNote, httpRequest, splitOut, snowflake. Scheduled trigger; 35 nodes.
HTTP Request, Snowflake, Slack
Import Productboard Notes, Companies and Features into Snowflake. Uses stickyNote, httpRequest, splitOut, snowflake. Scheduled trigger; 35 nodes.
HTTP Request, Snowflake, Slack
This workflow imports Productboard data into Snowflake, automating data extraction, mapping, and updates for features, companies, and notes. It supports scheduled weekly updates, data cleansing, and S
HTTP Request, Snowflake, Slack
This workflow streamlines the entire inventory replenishment process by leveraging AI for demand forecasting and intelligent logic for supplier selection. It aggregates data from multiple sources—POS
HTTP Request, MySQL, Slack