飯盛 正幹 This workflow corresponds to n8n.io template #12113 — we link there as the canonical source.
This workflow follows the Gmail → Google Sheets 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": "Generate invoices and send payment reminders with escalation using Google Sheets",
"nodes": [
{
"id": "sticky-overview",
"name": "Sticky Note",
"type": "n8n-nodes-base.stickyNote",
"position": [
-280,
80
],
"parameters": {
"width": 400,
"height": 560,
"content": "## Generate invoices and send payment reminders with escalation\n\n### Who is this for?\nFreelancers, small businesses, and finance teams who need automated invoice management with intelligent payment follow-ups.\n\n### What this workflow does\n**Invoice Generation:**\n- Receives order data with line items\n- Splits and calculates each line item\n- Aggregates totals and saves to Sheets\n- Sends invoice email with payment link\n\n**Payment Reminders:**\n- Daily check for overdue invoices\n- Loops through unpaid items\n- 5-level escalation via Switch node\n- Slack notification for collections\n\n### Setup\n1. Create Google Sheet with invoice columns\n2. Connect Google Sheets and Gmail\n3. Configure Slack for escalations\n\n### Requirements\n- Google Sheets\n- Gmail account\n- Slack workspace"
},
"typeVersion": 1
},
{
"id": "sticky-step1",
"name": "Sticky Note1",
"type": "n8n-nodes-base.stickyNote",
"position": [
180,
180
],
"parameters": {
"color": 7,
"width": 280,
"height": 80,
"content": "**Step 1: Invoice Creation**\nReceive order data, generate invoice ID, and initialize invoice fields."
},
"typeVersion": 1
},
{
"id": "sticky-step2",
"name": "Sticky Note2",
"type": "n8n-nodes-base.stickyNote",
"position": [
560,
180
],
"parameters": {
"color": 7,
"width": 300,
"height": 80,
"content": "**Step 2: Line Item Processing**\nSplit Out each line item, calculate totals, and Aggregate results."
},
"typeVersion": 1
},
{
"id": "sticky-step3",
"name": "Sticky Note3",
"type": "n8n-nodes-base.stickyNote",
"position": [
1320,
420
],
"parameters": {
"color": 7,
"width": 320,
"height": 80,
"content": "**Step 3: Daily Overdue Check**\nSchedule Trigger runs daily. Loop Over batches each invoice for processing."
},
"typeVersion": 1
},
{
"id": "sticky-step4",
"name": "Sticky Note4",
"type": "n8n-nodes-base.stickyNote",
"position": [
1980,
180
],
"parameters": {
"color": 7,
"width": 320,
"height": 80,
"content": "**Step 4: Reminder Escalation**\nSwitch routes to 5 reminder levels based on days overdue. Collections at 60+ days."
},
"typeVersion": 1
},
{
"id": "webhook-invoice",
"name": "New Invoice Request",
"type": "n8n-nodes-base.webhook",
"position": [
180,
300
],
"parameters": {
"path": "create-invoice",
"options": {},
"httpMethod": "POST",
"responseMode": "responseNode"
},
"typeVersion": 2
},
{
"id": "init-invoice",
"name": "Initialize Invoice",
"type": "n8n-nodes-base.set",
"position": [
400,
300
],
"parameters": {
"mode": "manual",
"options": {},
"assignments": {
"assignments": [
{
"id": "1",
"name": "invoiceId",
"type": "string",
"value": "={{ 'INV-' + $now.format('yyyy') + '-' + String(Math.floor(Math.random() * 9000) + 1000) }}"
},
{
"id": "2",
"name": "clientName",
"type": "string",
"value": "={{ $json.body.clientName }}"
},
{
"id": "3",
"name": "clientEmail",
"type": "string",
"value": "={{ $json.body.clientEmail }}"
},
{
"id": "4",
"name": "lineItems",
"type": "object",
"value": "={{ $json.body.lineItems }}"
},
{
"id": "5",
"name": "paymentTerms",
"type": "number",
"value": "={{ $json.body.paymentTerms || 30 }}"
},
{
"id": "6",
"name": "taxRate",
"type": "number",
"value": "={{ $json.body.taxRate || 0.1 }}"
},
{
"id": "7",
"name": "createdAt",
"type": "string",
"value": "={{ $now.toISO() }}"
},
{
"id": "8",
"name": "dueDate",
"type": "string",
"value": "={{ $now.plus({ days: $json.body.paymentTerms || 30 }).toISODate() }}"
}
]
},
"duplicateItem": false
},
"typeVersion": 3.4
},
{
"id": "split-line-items",
"name": "Split Line Items",
"type": "n8n-nodes-base.splitOut",
"position": [
620,
300
],
"parameters": {
"include": "allOtherFields",
"options": {},
"fieldToSplitOut": "lineItems"
},
"typeVersion": 1
},
{
"id": "calc-line-total",
"name": "Calculate Line Total",
"type": "n8n-nodes-base.code",
"position": [
840,
300
],
"parameters": {
"jsCode": "const item = $input.first().json;\nconst lineItem = item.lineItems;\n\nconst quantity = lineItem.quantity || 1;\nconst rate = lineItem.rate || 0;\nconst lineTotal = quantity * rate;\n\nreturn [{\n json: {\n invoiceId: item.invoiceId,\n clientName: item.clientName,\n clientEmail: item.clientEmail,\n taxRate: item.taxRate,\n dueDate: item.dueDate,\n lineItem: {\n description: lineItem.description,\n quantity: quantity,\n rate: rate,\n lineTotal: lineTotal\n }\n }\n}];"
},
"typeVersion": 2
},
{
"id": "aggregate-lines",
"name": "Aggregate Line Items",
"type": "n8n-nodes-base.aggregate",
"position": [
1060,
300
],
"parameters": {
"options": {},
"aggregate": "aggregateAllItemData",
"destinationFieldName": "processedLines"
},
"typeVersion": 1
},
{
"id": "build-invoice",
"name": "Build Invoice Object",
"type": "n8n-nodes-base.code",
"position": [
1280,
300
],
"parameters": {
"jsCode": "const data = $input.first().json;\nconst lines = data.processedLines || [];\n\nconst invoiceId = lines[0]?.invoiceId || 'unknown';\nconst clientName = lines[0]?.clientName || '';\nconst clientEmail = lines[0]?.clientEmail || '';\nconst taxRate = lines[0]?.taxRate || 0.1;\nconst dueDate = lines[0]?.dueDate || '';\n\nconst subtotal = lines.reduce((sum, l) => sum + (l.lineItem?.lineTotal || 0), 0);\nconst tax = Math.round(subtotal * taxRate * 100) / 100;\nconst total = subtotal + tax;\n\nconst paymentLink = `https://pay.company.com/invoice/${invoiceId}`;\n\nreturn [{\n json: {\n invoiceId: invoiceId,\n clientName: clientName,\n clientEmail: clientEmail,\n lineItems: lines.map(l => l.lineItem),\n subtotal: subtotal,\n taxRate: taxRate,\n tax: tax,\n total: total,\n dueDate: dueDate,\n paymentLink: paymentLink,\n status: 'pending',\n createdAt: new Date().toISOString()\n }\n}];"
},
"typeVersion": 2
},
{
"id": "save-invoice",
"name": "Save Invoice to Sheet",
"type": "n8n-nodes-base.googleSheets",
"position": [
1500,
300
],
"parameters": {
"columns": {
"value": {
"Tax": "={{ $json.tax }}",
"Email": "={{ $json.clientEmail }}",
"Total": "={{ $json.total }}",
"Client": "={{ $json.clientName }}",
"Status": "={{ $json.status }}",
"Created": "={{ $json.createdAt }}",
"Due Date": "={{ $json.dueDate }}",
"Subtotal": "={{ $json.subtotal }}",
"Invoice ID": "={{ $json.invoiceId }}",
"Last Reminder": ""
},
"mappingMode": "defineBelow"
},
"options": {},
"operation": "append",
"sheetName": {
"__rl": true,
"mode": "list",
"value": "Invoices"
},
"documentId": {
"__rl": true,
"mode": "list",
"value": ""
}
},
"typeVersion": 4.5
},
{
"id": "send-invoice-email",
"name": "Send Invoice Email",
"type": "n8n-nodes-base.gmail",
"position": [
1720,
300
],
"parameters": {
"sendTo": "={{ $json.clientEmail }}",
"message": "=Dear {{ $json.clientName }},\n\nPlease find your invoice details:\n\nInvoice: {{ $json.invoiceId }}\nAmount: ${{ $json.total.toFixed(2) }}\nDue Date: {{ $json.dueDate }}\n\nPay now: {{ $json.paymentLink }}\n\nThank you!",
"options": {},
"subject": "=Invoice {{ $json.invoiceId }} from Company"
},
"typeVersion": 2.1
},
{
"id": "invoice-response",
"name": "Invoice Created Response",
"type": "n8n-nodes-base.respondToWebhook",
"position": [
1940,
300
],
"parameters": {
"respondWith": "json",
"responseBody": "={{ JSON.stringify({ success: true, invoiceId: $json.invoiceId, total: $json.total, dueDate: $json.dueDate }) }}"
},
"typeVersion": 1.1
},
{
"id": "daily-check",
"name": "Daily Overdue Check",
"type": "n8n-nodes-base.scheduleTrigger",
"position": [
1320,
540
],
"parameters": {
"rule": {
"interval": [
{
"field": "hours",
"triggerAtHour": 9
}
]
}
},
"typeVersion": 1.2
},
{
"id": "get-unpaid",
"name": "Get Unpaid Invoices",
"type": "n8n-nodes-base.googleSheets",
"position": [
1540,
540
],
"parameters": {
"options": {},
"filtersUI": {
"values": [
{
"lookupValue": "pending",
"lookupColumn": "Status"
}
]
},
"operation": "getMany",
"sheetName": {
"__rl": true,
"mode": "list",
"value": "Invoices"
},
"documentId": {
"__rl": true,
"mode": "list",
"value": ""
}
},
"typeVersion": 4.5
},
{
"id": "calc-overdue",
"name": "Calculate Overdue Days",
"type": "n8n-nodes-base.code",
"position": [
1760,
540
],
"parameters": {
"jsCode": "const invoices = $input.all();\nconst today = new Date();\n\nconst overdueInvoices = invoices.map(inv => {\n const dueDate = new Date(inv.json['Due Date']);\n const daysOverdue = Math.floor((today - dueDate) / (1000 * 60 * 60 * 24));\n \n let reminderLevel = 'none';\n if (daysOverdue >= 60) reminderLevel = 'collections';\n else if (daysOverdue >= 31) reminderLevel = 'final';\n else if (daysOverdue >= 15) reminderLevel = 'urgent';\n else if (daysOverdue >= 8) reminderLevel = 'second';\n else if (daysOverdue >= 1) reminderLevel = 'first';\n \n return {\n json: {\n invoiceId: inv.json['Invoice ID'],\n clientName: inv.json['Client'],\n clientEmail: inv.json['Email'],\n total: parseFloat(inv.json['Total']) || 0,\n dueDate: inv.json['Due Date'],\n daysOverdue: daysOverdue,\n reminderLevel: reminderLevel\n }\n };\n}).filter(inv => inv.json.daysOverdue > 0);\n\nreturn overdueInvoices;"
},
"typeVersion": 2
},
{
"id": "loop-invoices",
"name": "Loop Over Invoices",
"type": "n8n-nodes-base.splitInBatches",
"position": [
1980,
540
],
"parameters": {
"options": {},
"batchSize": 1
},
"typeVersion": 3
},
{
"id": "route-reminder",
"name": "Route by Reminder Level",
"type": "n8n-nodes-base.switch",
"position": [
2200,
540
],
"parameters": {
"rules": {
"values": [
{
"outputKey": "First",
"conditions": {
"combinator": "and",
"conditions": [
{
"operator": {
"type": "string",
"operation": "equals"
},
"leftValue": "={{ $json.reminderLevel }}",
"rightValue": "first"
}
]
}
},
{
"outputKey": "Second",
"conditions": {
"combinator": "and",
"conditions": [
{
"operator": {
"type": "string",
"operation": "equals"
},
"leftValue": "={{ $json.reminderLevel }}",
"rightValue": "second"
}
]
}
},
{
"outputKey": "Urgent",
"conditions": {
"combinator": "and",
"conditions": [
{
"operator": {
"type": "string",
"operation": "equals"
},
"leftValue": "={{ $json.reminderLevel }}",
"rightValue": "urgent"
}
]
}
},
{
"outputKey": "Final",
"conditions": {
"combinator": "and",
"conditions": [
{
"operator": {
"type": "string",
"operation": "equals"
},
"leftValue": "={{ $json.reminderLevel }}",
"rightValue": "final"
}
]
}
},
{
"outputKey": "Collections",
"conditions": {
"combinator": "and",
"conditions": [
{
"operator": {
"type": "string",
"operation": "equals"
},
"leftValue": "={{ $json.reminderLevel }}",
"rightValue": "collections"
}
]
}
}
]
},
"options": {
"fallbackOutput": "none"
}
},
"typeVersion": 3.2
},
{
"id": "first-reminder",
"name": "First Reminder Email",
"type": "n8n-nodes-base.gmail",
"position": [
2440,
320
],
"parameters": {
"sendTo": "={{ $json.clientEmail }}",
"message": "=Hi {{ $json.clientName }},\n\nThis is a friendly reminder that invoice {{ $json.invoiceId }} for ${{ $json.total.toFixed(2) }} was due on {{ $json.dueDate }}.\n\nPlease process payment at your earliest convenience.\n\nThank you!",
"options": {},
"subject": "=Reminder: Invoice {{ $json.invoiceId }} is Due"
},
"typeVersion": 2.1
},
{
"id": "second-reminder",
"name": "Second Reminder Email",
"type": "n8n-nodes-base.gmail",
"position": [
2440,
460
],
"parameters": {
"sendTo": "={{ $json.clientEmail }}",
"message": "=Dear {{ $json.clientName }},\n\nYour invoice {{ $json.invoiceId }} is now {{ $json.daysOverdue }} days overdue.\n\nAmount: ${{ $json.total.toFixed(2) }}\n\nPlease arrange payment immediately.",
"options": {},
"subject": "=Second Notice: Invoice {{ $json.invoiceId }}"
},
"typeVersion": 2.1
},
{
"id": "urgent-reminder",
"name": "Urgent Reminder Email",
"type": "n8n-nodes-base.gmail",
"position": [
2440,
600
],
"parameters": {
"sendTo": "={{ $json.clientEmail }}",
"message": "=Dear {{ $json.clientName }},\n\nURGENT: Your account has an outstanding balance of ${{ $json.total.toFixed(2) }} that is {{ $json.daysOverdue }} days past due.\n\nPlease contact us immediately.",
"options": {},
"subject": "=URGENT: Invoice {{ $json.invoiceId }}"
},
"typeVersion": 2.1
},
{
"id": "final-reminder",
"name": "Final Notice Email",
"type": "n8n-nodes-base.gmail",
"position": [
2440,
740
],
"parameters": {
"sendTo": "={{ $json.clientEmail }}",
"message": "=Dear {{ $json.clientName }},\n\nFINAL NOTICE: Invoice {{ $json.invoiceId }} is now {{ $json.daysOverdue }} days overdue.\n\nAmount: ${{ $json.total.toFixed(2) }}\n\nThis is your final notice before collections.",
"options": {},
"subject": "=FINAL NOTICE: Invoice {{ $json.invoiceId }}"
},
"typeVersion": 2.1
},
{
"id": "collections-slack",
"name": "Escalate to Collections",
"type": "n8n-nodes-base.slack",
"position": [
2440,
880
],
"parameters": {
"text": "=:warning: *Collections Escalation*\n\nInvoice: {{ $json.invoiceId }}\nClient: {{ $json.clientName }}\nAmount: ${{ $json.total.toFixed(2) }}\nDays Overdue: {{ $json.daysOverdue }}",
"select": "channel",
"resource": "message",
"channelId": {
"__rl": true,
"mode": "name",
"value": "#collections"
},
"operation": "post",
"otherOptions": {}
},
"typeVersion": 2.2
},
{
"id": "merge-reminders",
"name": "Merge Reminder Paths",
"type": "n8n-nodes-base.merge",
"position": [
2680,
540
],
"parameters": {
"mode": "chooseBranch",
"options": {}
},
"typeVersion": 3
},
{
"id": "update-reminder-date",
"name": "Update Reminder Date",
"type": "n8n-nodes-base.googleSheets",
"position": [
2900,
540
],
"parameters": {
"columns": {
"value": {
"Invoice ID": "={{ $json.invoiceId }}",
"Last Reminder": "={{ $now.toISO() }}"
},
"mappingMode": "defineBelow"
},
"options": {},
"operation": "update",
"sheetName": {
"__rl": true,
"mode": "list",
"value": "Invoices"
},
"documentId": {
"__rl": true,
"mode": "list",
"value": ""
}
},
"typeVersion": 4.5
},
{
"id": "continue-loop",
"name": "Continue Loop",
"type": "n8n-nodes-base.code",
"position": [
3120,
540
],
"parameters": {
"jsCode": "return $input.all();"
},
"typeVersion": 2
}
],
"settings": {
"executionOrder": "v1"
},
"connections": {
"Continue Loop": {
"main": [
[
{
"node": "Loop Over Invoices",
"type": "main",
"index": 0
}
]
]
},
"Split Line Items": {
"main": [
[
{
"node": "Calculate Line Total",
"type": "main",
"index": 0
}
]
]
},
"Final Notice Email": {
"main": [
[
{
"node": "Merge Reminder Paths",
"type": "main",
"index": 0
}
]
]
},
"Initialize Invoice": {
"main": [
[
{
"node": "Split Line Items",
"type": "main",
"index": 0
}
]
]
},
"Loop Over Invoices": {
"main": [
[
{
"node": "Route by Reminder Level",
"type": "main",
"index": 0
}
],
[]
]
},
"Send Invoice Email": {
"main": [
[
{
"node": "Invoice Created Response",
"type": "main",
"index": 0
}
]
]
},
"Daily Overdue Check": {
"main": [
[
{
"node": "Get Unpaid Invoices",
"type": "main",
"index": 0
}
]
]
},
"Get Unpaid Invoices": {
"main": [
[
{
"node": "Calculate Overdue Days",
"type": "main",
"index": 0
}
]
]
},
"New Invoice Request": {
"main": [
[
{
"node": "Initialize Invoice",
"type": "main",
"index": 0
}
]
]
},
"Aggregate Line Items": {
"main": [
[
{
"node": "Build Invoice Object",
"type": "main",
"index": 0
}
]
]
},
"Build Invoice Object": {
"main": [
[
{
"node": "Save Invoice to Sheet",
"type": "main",
"index": 0
}
]
]
},
"Calculate Line Total": {
"main": [
[
{
"node": "Aggregate Line Items",
"type": "main",
"index": 0
}
]
]
},
"First Reminder Email": {
"main": [
[
{
"node": "Merge Reminder Paths",
"type": "main",
"index": 0
}
]
]
},
"Merge Reminder Paths": {
"main": [
[
{
"node": "Update Reminder Date",
"type": "main",
"index": 0
}
]
]
},
"Update Reminder Date": {
"main": [
[
{
"node": "Continue Loop",
"type": "main",
"index": 0
}
]
]
},
"Save Invoice to Sheet": {
"main": [
[
{
"node": "Send Invoice Email",
"type": "main",
"index": 0
}
]
]
},
"Second Reminder Email": {
"main": [
[
{
"node": "Merge Reminder Paths",
"type": "main",
"index": 0
}
]
]
},
"Urgent Reminder Email": {
"main": [
[
{
"node": "Merge Reminder Paths",
"type": "main",
"index": 0
}
]
]
},
"Calculate Overdue Days": {
"main": [
[
{
"node": "Loop Over Invoices",
"type": "main",
"index": 0
}
]
]
},
"Escalate to Collections": {
"main": [
[
{
"node": "Merge Reminder Paths",
"type": "main",
"index": 0
}
]
]
},
"Route by Reminder Level": {
"main": [
[
{
"node": "First Reminder Email",
"type": "main",
"index": 0
}
],
[
{
"node": "Second Reminder Email",
"type": "main",
"index": 0
}
],
[
{
"node": "Urgent Reminder Email",
"type": "main",
"index": 0
}
],
[
{
"node": "Final Notice Email",
"type": "main",
"index": 0
}
],
[
{
"node": "Escalate to Collections",
"type": "main",
"index": 0
}
]
]
}
}
}
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About this workflow
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.
Source: https://n8n.io/workflows/12113/ — original creator credit. Request a take-down →
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