What can I create using the Ledgerly Billing API?

You can create GST and non-GST invoices directly from your software: send customer, product and tax details, and Ledgerly calculates CGST, SGST and IGST, generates the invoice number, produces a PDF and returns all totals. You can also retrieve invoices, look them up by your own order reference, cancel invoices and record payments.

Does the API calculate CGST, SGST and IGST?

Yes. Ledgerly applies the correct tax split automatically based on the place of supply and GST rate on each line item, and returns the CGST, SGST and IGST amounts in the response.

How are duplicate invoices prevented?

Invoice creation requires an Idempotency-Key header. Retrying with the same key and payload returns the original invoice. Reusing a reference returns a duplicate error, so network retries never create double invoices.

Ledgerly Billing API · Made for India

Add GST Billing to Your Software with Ledgerly APIs

Q: What is the difference between Billing Core and Billing Suite?

Billing Core (₹999/month) covers invoices, payment recording and webhooks — the essentials to bill from your software. Billing Suite (₹1,999/month) adds customers, products, quotations, payment links, payments listing, reports and statements for a complete billing back office. Both plans include sandbox and production keys and cover one registered business (one GSTIN).

Q: Can I test before going live?

Yes. Every partner receives sandbox credentials and documentation to test invoice creation, GST calculations, PDF layout, cancellation and webhooks before production keys are issued.

Q: Can I use my own order ID?

Yes. Every invoice carries your external_reference (your order or reference ID). It must be unique per account and you can look up an invoice directly by that reference.

Integrate GST and non-GST invoice generation, automatic tax calculations, downloadable invoice PDFs, payment recording and real-time webhooks into your SaaS, ERP, POS or business application.

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Prefer to talk first? Message us on WhatsApp — or fill the form for sandbox access. Built for Indian software products, SaaS platforms, ERPs, POS systems and marketplaces.

curl --request POST \
  --url https://api.ledgerly.biz/api/v1/partner/invoices \
  --header "Authorization: Bearer lgy_live_YOUR_API_KEY" \
  --header "Idempotency-Key: ORDER-1001-INVOICE" \
  --header "Content-Type: application/json" \
  --data '{
    "external_reference": "ORDER-1001",
    "invoice_date": "2026-07-21",
    "customer": {
      "name": "ABC Traders",
      "gstin": "23ABCDE1234F1Z5"
    },
    "place_of_supply": "Madhya Pradesh",
    "items": [
      {
        "name": "Software Service",
        "quantity": 1,
        "unit_price": 10000,
        "gst_rate": 18
      }
    ]
  }'

const res = await fetch(
  "https://api.ledgerly.biz/api/v1/partner/invoices",
  {
    method: "POST",
    headers: {
      "Authorization": "Bearer lgy_live_YOUR_API_KEY",
      "Idempotency-Key": "ORDER-1001-INVOICE",
      "Content-Type": "application/json"
    },
    body: JSON.stringify({
      external_reference: "ORDER-1001",
      invoice_date: "2026-07-21",
      customer: { name: "ABC Traders", gstin: "23ABCDE1234F1Z5" },
      place_of_supply: "Madhya Pradesh",
      items: [
        { name: "Software Service", quantity: 1, unit_price: 10000, gst_rate: 18 }
      ]
    })
  }
);
const invoice = await res.json();

import requests

res = requests.post(
    "https://api.ledgerly.biz/api/v1/partner/invoices",
    headers={
        "Authorization": "Bearer lgy_live_YOUR_API_KEY",
        "Idempotency-Key": "ORDER-1001-INVOICE",
        "Content-Type": "application/json",
    },
    json={
        "external_reference": "ORDER-1001",
        "invoice_date": "2026-07-21",
        "customer": {"name": "ABC Traders", "gstin": "23ABCDE1234F1Z5"},
        "place_of_supply": "Madhya Pradesh",
        "items": [
            {"name": "Software Service", "quantity": 1,
             "unit_price": 10000, "gst_rate": 18}
        ],
    },
)
invoice = res.json()

One integration adds India-ready billing to

POS software ERP systems SaaS platforms Marketplaces CRM & service apps Logistics platforms Vertical software

The hidden cost of DIY billing

Building Billing Internally Takes More Than Generating a PDF

A billing module may look simple at first, but production billing requires tax calculations, invoice numbering, PDF generation, payment tracking, retries, audit history and reliable document states.

Ledgerly provides these capabilities through developer-friendly APIs so your team can focus on its main product instead of maintaining an invoice engine.

GST & non-GST invoices
CGST, SGST & IGST logic
Place-of-supply rules
Invoice numbering
Discounts & rounding
Customer & product details
Invoice PDF generation
Partial & full payments
Duplicate-request protection
Invoice cancellation
Audit records
Webhook notifications

Capabilities

Everything Required for Billing Integration

Production-ready building blocks, exposed as clean REST endpoints — nothing you have to build or maintain yourself.

GST & non-GST invoices

Create fully compliant GST invoices or plain non-GST bills from a single endpoint.

Automatic CGST / SGST / IGST

Tax split is derived from place of supply and each line's GST rate — no tax code on your side.

Invoice PDF generation

Every issued invoice produces a standard Ledgerly PDF, delivered via a short-lived signed URL.

Idempotent creation

An Idempotency-Key makes retries safe — the same request never creates a duplicate invoice.

Full & partial payments

Record payments against an invoice and track amount paid, amount due and status.

Signed webhooks

HMAC-SHA256 signed events for invoice.created, invoice.paid and invoice.cancelled.

External order references

Attach your own order ID to every invoice and look invoices up by that reference.

Partner dashboard

Review invoices, outstanding balances, webhooks and request activity from the Ledgerly web app.

Revocable API credentials

Issue, rotate and revoke keys instantly — each key is scoped to your registered business.

Request logs

Authentication and request logs give you and Ledgerly a clear audit trail for every call.

How it works

Integrate Billing in Four Steps

From first request to production, most partners are live in days — not weeks.

Request sandbox access

Tell us about your product and receive test credentials, documentation and the Postman collection.

Create the first invoice

Send customer, product, GST and payment information to POST /v1/partner/invoices.

Test PDFs & webhooks

Verify invoice formatting, GST totals, payment updates and signed webhook events.

Move to production

Complete verification and activate your production credentials to go live.

Start Your Sandbox Integration

One request, complete invoice

One Request, Complete Invoice Response

Send the essentials — Ledgerly finalizes the invoice, calculates GST, assigns a number and returns everything, including the PDF link.

Response · 201 Created

JSON

{
  "success": true,
  "invoice_id": "inv_a1b2c3d4e5f6g7h8i9j0",
  "external_reference": "ORDER-1001",
  "invoice_number": "INV-2026-0041",
  "status": "ISSUED",
  "subtotal": 10000,
  "taxable_amount": 10000,
  "tax_amount": 1800,
  "cgst": 900,
  "sgst": 900,
  "igst": 0,
  "grand_total": 11800,
  "amount_paid": 0,
  "amount_due": 11800,
  "pdf_url": "/v1/partner/invoices/inv_a1b2c3d4e5f6g7h8i9j0/pdf",
  "created_at": "2026-07-21T10:30:00"
}

Generated invoice preview

INV-2026-0041

ABC Traders · GSTIN 23ABCDE1234F1Z5

Place of supply: Madhya Pradesh

Issued

Item	Qty	Rate	GST	Amount
Software Service	1	₹10,000	18%	₹10,000

Taxable value₹10,000

CGST @ 9%₹900

SGST @ 9%₹900

Grand total₹11,800

Illustrative example. No real API keys, GSTINs or customer records are shown.

Where it fits

Built for Software Products Across Industries

Add billing without developing and maintaining an independent invoice engine.

POS software

Generate a GST invoice and PDF directly after a retail transaction, with your bill number as the reference.

ERP software

Issue invoices from sales orders and reconcile payments without building a tax engine into your ERP.

SaaS platforms

Bill subscribers with correct CGST/SGST/IGST and hand them a compliant downloadable invoice.

Marketplaces

Produce seller and buyer invoices per order and notify your systems through webhooks.

CRM & service software

Turn a closed deal or completed job into a GST invoice without leaving your workflow.

Logistics platforms

Invoice shipments and services with HSN/SAC codes and place-of-supply handled for you.

School, clinic & vertical software

Add fee and service billing to niche vertical apps with a single, consistent invoice format.

API + dashboard

API Automation with a Ready-to-Use Billing Dashboard

Ledgerly is not only an invoice API. Your software automates billing through APIs, while authorized business users manage exceptions in the Ledgerly web or mobile app.

Partner software

Automated, through the API

Create invoices
Record payments
Receive webhooks
Download PDFs

Ledgerly dashboard

Hands-on, for your business users

Review invoices
Track outstanding balances
Manage customers
Access reports

Developer experience

Designed for a Faster Developer Integration

Predictable REST endpoints, clear errors and the tooling your team already expects — so integration is a few days of work, not a project.

RESTful JSON APIs
Sandbox & production keys
Stable error codes
Request IDs
Idempotency support
Request logs
Signed webhooks
Postman collection
Integration assistance
Clear API documentation

Read the Integration Guide Download Postman Collection

Verify your key

curl https://api.ledgerly.biz/api/v1/partner/ping \
  -H "Authorization: Bearer lgy_live_YOUR_API_KEY"

# 200 OK
{
  "success": true,
  "partner_account_id": 1,
  "message": "Partner API authentication successful"
}

Every error returns a stable code, a human message and per-field detail where relevant.

Security

Built with Secure Partner Access

Only capabilities that are actually in place — described plainly, without exaggerated claims.

HTTPS-only accessAll partner API traffic is encrypted in transit.

Separate API credentialsDistinct sandbox and production keys, never your app login.

Revocable API keysRotate or revoke a key instantly if it is ever exposed.

Business-scoped authorizationEach key maps to one registered business — no cross-account access.

Short-lived PDF URLsInvoice PDFs are served through signed, time-limited links.

Signed webhooksHMAC-SHA256 signatures let you verify every delivery.

Request logsAuthentication and request activity are logged for audit.

Rate limitsPer-account limits protect stability and return a Retry-After.

Idempotency protectionDuplicate-request protection is enforced on invoice creation.

Pricing

Two Simple Partner API Plans

Start with core invoicing, or unlock the full billing suite. Introductory partner pricing, per registered business — taxes extra.

60 / minRate limit

100Max line items

EnabledPayments

SandboxTest account

Starter

Billing Core

₹999 / month

Core invoicing API for one registered business (one GSTIN)

Invoices
Payment recording
Webhooks

Start with Billing Core

Full billing suite

Billing Suite

₹1,999 / month

Everything in Core plus customers, products, quotations, payment links & reports

Customers
Invoices
Payments listing
Payment links
Payment recording
Products
Quotations
Reports
Statements
Webhooks

Apply for Billing Suite

Both plans include sandbox & production keys, idempotent invoice creation, signed webhooks and basic integration assistance. Prices are per registered business (one GSTIN) and exclude taxes. Custom development, government e-invoicing (IRN), e-way bills, multiple connected businesses, white-label usage and reseller rights are priced separately. Contact us for embedded partner pricing.

FAQ

Frequently Asked Questions

GST and non-GST invoices, directly from your software. You send customer, product and tax details; Ledgerly calculates CGST, SGST and IGST, assigns an invoice number, generates a PDF and returns all totals. You can also retrieve invoices, look them up by your own order reference, cancel invoices and record payments.

Yes. You receive sandbox credentials and documentation to test invoice creation, GST calculations, PDF layout, cancellation and webhooks before production keys are issued.

Billing Core (₹999/month) covers invoices, payment recording and webhooks — the essentials to bill directly from your software. Billing Suite (₹1,999/month) adds customers, products, quotations, payment links, payments listing, reports and statements for a full billing back office. Both include sandbox and production keys and cover one registered business (one GSTIN).

Yes. The correct tax split is applied automatically from the place_of_supply and each line's gst_rate, and the CGST, SGST and IGST amounts are returned in the response.

Yes. Every invoice carries your external_reference (your order or reference ID). It must be unique per account, and you can fetch an invoice directly by that reference.

Invoice creation requires an Idempotency-Key header. Retrying with the same key and payload returns the original invoice, and a repeated external_reference returns a duplicate error — so network retries never create double invoices.

Both the Billing Core and Billing Suite plans cover one registered business and one GSTIN. Connecting multiple businesses, or offering billing to your own customers, is available under separate embedded-partner pricing.

Government e-invoicing (IRN) and e-way bills are not part of the Billing Core or Billing Suite plans. They can be scoped and priced separately.

White-label PDFs, reselling and sublicensing are not included in the Billing Core or Billing Suite plans and require a separate partner or reseller agreement.

Yes. Basic integration support is included during business hours — authentication, request format, sandbox testing and genuine API defects. Custom development and extensive troubleshooting may be quoted separately.

Ready to Add GST Billing to Your Software?

Test invoice generation, GST calculations, PDFs, payments and webhooks using the Ledgerly sandbox.

Get Sandbox Access Book an Integration Demo

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