Invoice Generator API — Generate PDF Invoices Programmatically
Integrate invoice generation into your application with our simple REST API. Send a JSON request, receive a professional PDF invoice. Trusted by developers worldwide.
What You Can Do With the Invoice Generator API
Generate PDF invoices from JSON
POST your invoice data as JSON and receive a professional PDF in response.
Full customization support
Business details, client info, line items, tax, discounts, logo URL, currency — all configurable.
GST-compliant invoices
Pass GSTIN, HSN/SAC codes, and CGST/SGST/IGST split for India-compliant invoices.
Webhook notifications
Receive webhooks when an invoice is viewed or marked paid (Starter plan and above).
Idempotent requests
Safe to retry failed requests. Pass an idempotency key to prevent duplicate invoice generation.
Multiple output formats
PDF (all plans) and UBL XML for electronic invoicing (Pro plan and above).
Getting Started in 5 Minutes
Three steps: get your API key, make your first request, receive your PDF.
curl -X POST https://api.quick-invoicegenerator.com/v1/invoices \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"business": {
"name": "Acme Design Studio",
"email": "billing@acme.com",
"address": "123 Main St, San Francisco, CA 94102"
},
"client": {
"name": "Client Corp Ltd",
"email": "accounts@clientcorp.com",
"address": "456 Business Ave, New York, NY 10001"
},
"invoice": {
"number": "INV-2026-001",
"date": "2026-04-06",
"due_date": "2026-05-06",
"currency": "USD"
},
"line_items": [
{
"description": "Website Design — Homepage",
"quantity": 1,
"unit_price": 1500.00
},
{
"description": "Monthly Retainer — April 2026",
"quantity": 1,
"unit_price": 800.00
}
],
"tax_rate": 10,
"notes": "Payment due within 30 days. Thank you!"
}' \
--output invoice-INV-2026-001.pdfconst axios = require('axios');
const fs = require('fs');
async function generateInvoice() {
const response = await axios.post(
'https://api.quick-invoicegenerator.com/v1/invoices',
{
business: { name: 'Acme Design Studio', email: 'billing@acme.com' },
client: { name: 'Client Corp', email: 'ap@client.com' },
invoice: { number: 'INV-001', date: '2026-04-06', currency: 'USD' },
line_items: [{ description: 'Design Services', quantity: 1, unit_price: 1500 }],
tax_rate: 10
},
{
headers: { 'Authorization': 'Bearer YOUR_API_KEY' },
responseType: 'arraybuffer'
}
);
fs.writeFileSync('invoice.pdf', response.data);
console.log('Invoice generated: invoice.pdf');
}
generateInvoice();import requests
response = requests.post(
'https://api.quick-invoicegenerator.com/v1/invoices',
headers={'Authorization': 'Bearer YOUR_API_KEY'},
json={
'business': {'name': 'Acme Studio', 'email': 'billing@acme.com'},
'client': {'name': 'Client Corp', 'email': 'ap@client.com'},
'invoice': {'number': 'INV-001', 'date': '2026-04-06', 'currency': 'USD'},
'line_items': [{'description': 'Services', 'quantity': 1, 'unit_price': 1500}],
'tax_rate': 10
}
)
with open('invoice.pdf', 'wb') as f:
f.write(response.content)
print('Invoice saved: invoice.pdf')API Pricing
Start free. Scale as you grow. No contracts.
- PDF output
- All customization fields
- HTTPS + JSON support
- Standard support
- Everything in Free
- Webhooks
- Email delivery API
- Priority support
- Everything in Starter
- White-label output
- UBL XML format
- SLA guarantee
- Everything in Pro
- Custom integration
- Dedicated support
- Custom SLA
Frequently Asked Questions
What does the Invoice Generator API return?▼
The API accepts a JSON payload describing your invoice (business details, client info, line items, tax, currency) and returns a PDF binary or a URL to download the generated PDF.
Is there a free tier for the API?▼
Yes. The free tier includes 100 invoice generations per month — sufficient for testing and low-volume applications.
Does the API support GST invoices?▼
Yes. Pass GSTIN, HSN/SAC codes, and tax type (CGST+SGST or IGST) in the payload and the API generates a fully GST-compliant invoice.
What authentication method does the API use?▼
API key authentication via the Authorization header: Authorization: Bearer YOUR_API_KEY. Get your free API key by creating an account.
Can I white-label invoices generated via the API?▼
Yes on paid plans. White-label removes all Invoice Generator branding and replaces it entirely with your own.
Start Building With the Invoice Generator API
Free tier: 100 invoices/month. No credit card required to get started.