E-invoice and E-way Bill API
Generate e-invoices and e-way bills from the system you already bill in.
We integrate GST e-invoice and e-way bill generation into your ERP, billing app or ecommerce platform through GST Suvidha Provider APIs: IRN and QR code capture, e-way bill creation and updates, cancellations and error handling.
- IRN and QR code
- E-way bills
- Error handling
Free 30-minute call with a senior specialist. Reply within one business day. Based in Jaipur, working with businesses across India.
- Discovery callFree 30 minutes with a senior specialist
- Scoped first phaseWritten scope, timeline and fixed price
- Build with weekly demosWorking software you can see every week
- Launch and supportGo-live with your team ready, then ongoing support
What is e-invoice and e-way bill API integration?
E-invoice and e-way bill API integration lets your billing or ERP system generate the invoice reference number, QR code and e-way bill automatically through a GST Suvidha Provider's API instead of manual portal entry. Stack18 builds it with validation, retries and cancellation handling. Applicability rules change, so confirm them with your CA.
Last reviewed 30 October 2026 by the Stack18 delivery team in Jaipur. Security and AI governance · Pricing · About Stack18
| What it covers | Invoice and IRN generation; E-way bill creation; Errors and cancellations; GSP integration; Reporting and audit. |
|---|---|
| Typical first step | Discovery Sprint: 2 weeks, fixed price. |
| Build route | Fixed-scope first release: agreed in discovery; fixed price after discovery. |
| Long-term option | Transformation Pod: 12–36 months, annual contract. |
| Measured by | E-invoice generation time; Error rate; Cancellation handling time; Manual portal entry hours. Each against an agreed baseline. |
| Governance | Human approval at 5 governance gates before anything reaches production. NDA available on request. |
| Delivery team | Based in Jaipur, India. A senior specialist replies within one business day. |
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E-invoice and E-way Bill API, end to end.
Each capability is delivered by the same team on the Agentic SDLC, with your approval at every critical step.
Invoice and IRN generation
Raise e-invoices from your billing screen.
- IRN and QR code capture
- Validation before submission
- Print with QR code
E-way bill creation
Transport details captured once.
- E-way bill from invoice
- Vehicle updates and extensions
- Bulk and consolidated bills
Errors and cancellations
Fix problems quickly.
- Readable error messages
- Cancellation within allowed windows
- Retry queue
GSP integration
Reliable connectivity.
- GSP API integration
- Credential and key handling
- Sandbox testing
Reporting and audit
Know what was filed.
- Status reports by invoice
- Audit trail
- Exception lists
A typical engagement, step by step.
Senior people lead every phase. Specialised AI agents on the Agentic SDLC handle the repetitive work, and nothing ships without your approval.
Discovery
Map how e-invoicing works today, the systems and data involved, and agree the first measurable outcome.
Design
Design the workflows, roles, integrations and approval points for e-invoicing.
Build in weekly demos
Your team sees working e-invoicing software every week, with changes agreed in the open.
Launch and support
Data migration, training, go-live support and a measured 30-day review against the baseline.
Start small. Scale when it works.
Every engagement begins with a short, fixed-price step so you can judge the fit before committing further. See pricing.
Discovery Sprint
Teams deciding scope and priorities before they commit.
- Duration
- 2 weeks
- Pricing
- Fixed price
- Scoped plan and timeline
- Team and fixed price
- Process map or prototype
Fixed-scope first release
Teams that know what they need built.
- Duration
- Agreed in discovery
- Pricing
- Fixed price after discovery
- Written scope and acceptance criteria
- Weekly demos
- Handover with documentation
Transformation Pod
Multi-system programmes that run for years.
- Duration
- 12–36 months
- Pricing
- Annual contract
- Dedicated cross-functional team
- Quarterly business reviews
- One accountable partner
What we have shipped, and what a typical engagement looks like.
Delivered projects link to the full case study. Illustrative scenarios describe typical engagements and are not named client results.
Distributor billing from a custom ERP
- Challenge
- Invoices uploaded in batches; e-way bills created per consignment.
- What we do
- API integration to generate IRN and e-way bills at billing time.
Scoped in a 2-week sprint
Free e-invoicing review
Tell us where e-invoicing hurts most. We map what to fix first, whether ready-made or custom fits, and a realistic first step.
- Where to start and why
- Ready-made vs custom view
- Indicative timeline
We agree targets before we start.
Every engagement has a baseline and a target on the measures that matter to you, reported at every read-out.
E-invoice and E-way Bill API questions.
Do you provide the GSP?
We integrate with a GSP of your choice through its APIs. Provider charges are separate.
Does this apply to my turnover?
Applicability and thresholds change over time. Please confirm with your CA. We build to your actual requirement.
Which systems can you integrate?
Custom ERPs, billing apps, ecommerce and some third-party accounting tools, depending on their interfaces.
What if the portal is down?
We queue requests and retry, and flag invoices that cannot be processed so staff can act.
Is this legal advice?
No. We provide engineering. Your CA should confirm compliance requirements.
Guides, comparisons and proof.
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Read →TrustSecurity, Data Protection & AI Governance
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Read →Let's scope your E-invoice and E-way Bill API project.
Tell us where you are and where you want to be. A senior specialist will reply within one business day with next steps.
- Free 30-minute consultation
- Indicative estimate after the call
- NDA available on request