AI copilot for e-invoicing
Give your accounting team power with control.
Greenstamp handles bulk invoicing, bill capture, reconciliation and pre-submission checks across every client you manage. Your accountants keep final approval on every invoice.
Mexico (SAT / CFDI) and the EU (PEPPOL / EN 16931 / ViDA)
- Issuer tax ID
- XAXX010101000
- Recipient tax ID
- XEXX010101000
- Document type
- CFDI 4.0 · Ingreso
- Payment method
- PUE · Transfer
Connects with the tools your clients already use.
- Microsoft Dynamics
- Xero
- QuickBooks
- Square
- Shopify
- Stripe
- DATEV
Trusted by accounting firms and finance teams
- Frankfurt School
- Apoyo Integral
- Contaura
- DER Logistic
- Sepro
The problem
Your best people spend a quarter of their week on manual e-invoicing.
Fifteen minutes per invoice. Thousands of tax codes that keep changing. Rejections that come back two days later and start the cycle over. Hiring more accountants doesn't fix this. It's a leverage problem, not a hiring problem.
Without a copilot
- Fifteen minutes per invoice, entered by hand
- Tax codes looked up one at a time, and re-checked when they change
- Rejections arrive two days later, so the work starts again
- Growth means more hires, not more capacity
With Greenstamp
- 100 invoices in five minutes instead of two days
- Bills captured automatically from email, WhatsApp or upload
- Reconciliation matched and tax codes suggested, not looked up
- Your accountant still approves every invoice
Product
Everything a firm needs to run e-invoicing at scale.
Built for teams that manage dozens of client companies, not one business.
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Multi-entity dashboard
Every client company in one place. Filter by entity, status or due date, and act on what needs attention first.
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White-label client portals
Each client gets a portal with your logo on your domain. They upload documents and approve invoices without emailing you.
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WhatsApp to invoice
Clients send a message or a photo on WhatsApp. Greenstamp drafts the invoice and routes it to your team for review.
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Bill capture
Supplier bills arrive by email, WhatsApp or upload. The copilot extracts the data and prepares the entry for approval.
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Tax-code suggestions
Product and service codes suggested from the line item, with the reasoning shown. No more hunting through catalogues.
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Pre-submission validation
20+ checks run before anything goes to the tax authority. Compliance rejections drop to near zero.
How it works
Set up in an afternoon. Approve from day one.
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Bring your clients on
Upload signing certificates and import client data. About five minutes per client.
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Configure the copilot
Set approval rules, naming conventions and tax defaults so it works the way your firm already works.
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Let Greenstamp do the heavy lifting
Bulk invoicing, bill capture, reconciliation and validation run in the background.
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Your team reviews and approves
Nothing reaches the tax authority until an accountant signs off.
- 96% less time on bulk invoicing
- 100 invoices processed in 5 minutes
- 20+ automatic validators
- 50+ client entities in one dashboard
What our customers say
We hit 55 clients with a team I'm proud of. Greenstamp lets us get to 150 without diluting what makes us good — my accountants still do the work that needs judgment, and the copilot handles the rest.
Mission
The best accountants shouldn't be limited by operational work.
Removing friction from e-invoicing lets firms grow and spend their time on the strategic work clients actually pay for.
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Clarity over complexity
Plain screens, plain language, and one obvious next step. If it needs a manual, we got it wrong.
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Your data, your control
AES-256 encryption at rest and in transit. No black boxes: every suggestion shows its reasoning.
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Bridge, not barrier
Compliance rules explained in plain language, so your team and your clients understand why a check failed.
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Built for the long term
Tax rules change every year. We build for the next ten, not the next release.
FAQ
Questions accountants ask us.
What is Greenstamp?
Greenstamp is an AI copilot for e-invoicing. It handles bulk invoicing, bill capture, bank reconciliation, tax-code suggestions and pre-submission validation for accounting firms and finance teams that manage many client companies. It supports Mexico (SAT / CFDI) and the EU (PEPPOL / EN 16931 / ViDA).
Does Greenstamp replace accountants?
No. Greenstamp absorbs the repetitive work. Your accountants keep the judgment, the client relationships and the final sign-off. Nothing is submitted to a tax authority without a human approving it.
How is this different from regular invoicing software?
Most invoicing tools are built for one business issuing its own invoices. Greenstamp is built for firms managing dozens of client companies at once, each with its own certificates, tax rules and approval flow, all in one dashboard.
How long does setup take?
About 15 minutes for your firm, then around 5 minutes per client to upload signing certificates and import their data. Most firms are approving their first invoices the same day.
Can client portals use our own domain?
Yes. Client portals are white-label: your logo, your colours and your domain. Your clients see your firm, not ours.
How does Greenstamp keep us compliant?
Every document runs through 20+ validation checks before submission, covering tax IDs, document types, payment methods, catalogue codes and totals. Errors are explained in plain language so they can be fixed before the tax authority ever sees them.
How is our data secured?
Data is encrypted with AES-256 at rest and in transit. Signing certificates are stored encrypted and used only to sign documents your team has approved. Your data is never used to train models for other customers.
Is there a free trial?
Yes, 14 days. Email sales@greenstamp.io or book a demo and we'll set it up on your firm's real workflow.
Built for accountants who want better tools, not fewer accountants.
See Greenstamp on your firm's actual workflow. 30 minutes, no slides.