For prospects
Marketing deck
The overview: what Beleggo does and for whom — from freelancer to software vendor.
XRechnung · ZUGFeRD · Peppol
Create and check e-invoices — right in your browser
No upload. No account. No cloud.
You must receive them since 2025 and send them from 2027 — and an invoice that breaks EN 16931 may be rejected by the recipient. Without a proper invoice, the input-VAT deduction is at risk. Check and create XRechnung, ZUGFeRD and Peppol here: in the browser, no account, no upload.
No account · no upload
Unlimited · no daily cap
Sending mandatory from 2027/2028
Real XML, validated locally against EN 16931 — no black box.
Play the tourThe solution
One tool, many shapes.
The same engine — local, no server, no JVM — from the browser tool to an embedded build inside your own product. What becomes possible for you:
Available
For tax practices
Batch-validate whole client folders, watch folders, multi-seat operation — and readiness reports on the practice’s letterhead, recording what a client’s software was tested against. No data-processing agreement needed and no professional-secrecy question, because the documents never leave the building.
See the scope →Available
For businesses
Open, check, repair, create and convert — in your browser, no account, no upload. Plus saved templates and PDF branding with your logo and a payment QR. No data egress, no cloud.
Try it now →Available
Developers & AI agents
A CLI for batch runs and CI pipelines, and an MCP server as a deterministic guardrail for AI pipelines: the AI writes, Beleggo checks.
On request
Software & ERP vendors
Embed the same engine inside your product — npm package, WASM, web component or binary. Close to the only JS/browser engine that validates without a JVM and without upload.
On request
Partners & white-label
Beleggo under your brand: your own branding, your own legal pages, your customer relationship. One static bundle per partner — no infrastructure of your own.
Proof, not promises
Your invoice never leaves your machine — and you can verify it yourself.
Other online checkers upload your invoice to a server and delete it "after 24 hours" or "after 7 days". With us it never arrives there — no data-processing agreement, and for tax firms no question of professional secrecy. That is not a promise — it is checkable:
- 1Open your browser DevTools (F12) and the "Network" tab.
- 2Drop an invoice into Beleggo and validate it.
- 3You will see no request carrying your invoice data — or pull the network cable: it keeps working.
New: local security
What stays, stays encrypted.
Invoice data never leaves the device — that was always true. What is new is what happens to the data that stays on it: stored encrypted, every action recorded and chained, and one backup that survives losing the browser.
Encrypted in the browser
Seller profile, customers, saved invoices and client records sit AES-encrypted in the browser database. No plain text is left in the browser profile, in a profile backup or in a synced folder — and none on screen during a screen share.
A log with a hash chain
Every action — checked, repaired, saved, deleted — is recorded and chained to the entry before it. The log is right there in the studio: grouped by day, filterable, and an entry opens the invoice or the check it was about.
Backup with a passphrase
Browser storage is not durable. One click writes a file encrypted with your passphrase, carrying the log’s check value with it — the only copy that survives losing this browser, and the way back onto a new machine.
No third-party code
A Content-Security-Policy leaves the app no room for foreign scripts, no CDN, no analytics. It is not merely asserted: a CI job serves every shipped surface under exactly those headers and runs a real invoice through it.
An attachment is untrusted input
An invoice comes from somebody else. Beleggo never puts an attachment’s own bytes in front of the browser — what it shows is what its reader made of them — and it reports what is wrong with the file name or the link: control characters that make a name display as something it is not, a path where a file name belongs, a reference that is not a web address. A javascript: link in an invoice is shown, and is not clickable.
Stated plainly: the key sits on the same device as the data. That protects against casual access and accidental disclosure — not against a stolen or seized device. Your operating system’s full-disk encryption is what protects that.
Conformance
The same verdict as the official validator.
Our engine is checked against 352 real test invoices and returns the same verdict as the official validators — the same rule base (KoSIT v1.6.2) that also underpins the Service-BW endpoint and the government routers.
Cross-checked with
352test invoices · 100% agreement
1,784 checks per invoice: 1,749 rules from the official Schematron, 21 mandatory particulars under § 14 UStG, 5 VAT risk rules, 9 attachment checks.
Ruleset status: EN 16931 2026-01-31 · XRechnung 3.0.2 (Schematron 2.5.0) · Peppol BIS 3.0.20 · NLCIUS 2.0.3.13 · CIUS-RO 1.0.9 · HR-CIUS 1.0.3 · CIUS-PT 2.1.1
352 samples checked against the official validators · 0 open disagreements — matrix public.
Receiving and sending — both covered
01
Incoming invoices
Receiving has been mandatory since 2025 — and a PDF by email is not an e-invoice. Open XRechnung, ZUGFeRD and Peppol files, view them in plain language and check validity before you book them.
02
Outgoing invoices
Sending becomes mandatory from 2027/2028. Create an EN 16931-valid invoice in under a minute — and check it before it goes out.
Tampered ZUGFeRD PDFs
When the printed page says something else than the data.
A ZUGFeRD invoice has two faces: the page a human reads and pays from, and the embedded XML the accounting system books. Change only the page and every XML-only validator still passes it — the file stays valid. Beleggo Studio reads both and reports where they contradict each other. Locally, with no upload.
- Bank account: the printed IBAN against BT-84 in the XML
- Grand total (BT-112) and invoice number (BT-1) on the page
- Text that sits in the PDF but is never displayed
- Fonts that print digits other than the ones they store
Sample DK-090 from the open data kit — the file is valid under EN 16931.
Visible page
DE02 1203 0000 0000 2020 51
Embedded XML
DE89 3704 0044 0532 0130 00
Auto-repair
Broken invoices almost fix themselves.
Three rings: deterministic fixes with no AI, concrete correction proposals to confirm, and AI only for the rest — the data only you or an agent can know. All local, nothing uploaded.
# Ring 1 — deterministic, no AI$ beleggo fix DK-074.cii.xml --validate● 1 fix: reordered <rsm:ExchangedDocument> validity: invalid → valid# Ring 2 — proposed, you confirm$ beleggo validate DK-067.ubl.xml --explain✗ BR-CL-04: currency code must be ISO 4217 value: "EU" suggestion: EUR# Ring 3 — AI fills the rest (still local)$ beleggo-mcp · repair_plan3 auto-fixed · 1 to confirm · 1 needs inputWatch
The whole studio, once through.
Check, repair, simulate the recipient, VAT, batches, creating and PDF import — eleven chapters, each explained first and then demonstrated live.
Recorded in the real studio — nothing staged.
Capabilities
One tool for the whole e-invoice.
Open, check, repair, create, convert — all locally in your browser, nothing uploaded.
Validate against EN 16931
XRechnung (UBL & CII), ZUGFeRD / Factur-X and Peppol BIS 3 — checked across five layers: XML schema, EN 16931, format, country CIUS and the PDF/A-3 container.
The verdict of the official validator
Cross-checked against the official KoSIT test invoices and the official KoSIT validator jar — proven in CI, not just claimed.
Fix errors automatically
Safe structural repairs plus value-preserving normalisations (whitespace, escaping, date format) — with a before/after diff. The original is kept; amounts, VAT and IBAN are never changed automatically.
Edit the source & check live
Correct any field directly, re-validate instantly, and download the corrected XML — or the repaired ZUGFeRD PDF.
Error → field
Click an error and instantly see which field of the invoice it means. The cryptic rule codes are mapped onto the document.
Convert formats
UBL ↔ CII ↔ ZUGFeRD PDF — locally, re-validated after conversion. Convert a rejected UBL to CII without uploading it.
ZUGFeRD PDF, double-checked
We check the PDF/A-3 container and reconcile the visible page against the embedded XML — catching mismatched totals or IBANs that XML-only checkers miss.
B2G preflight & Leitweg-ID
Check before you send whether the invoice will pass a public authority — including the Leitweg-ID with its check digits (which the standard rules don’t verify).
Error library
1,749 validation rules explained in plain language and linked from every result — no more guessing what BR-DE-15 or BR-CO-10 mean. All 215 XRechnung and Peppol rules are written out, in German, English and French.
UBL and CII, side by side
The same rule is named differently in each syntax. Every rule page shows both paths together — which is exactly why checking a CII file against the UBL rules gives you a wall of errors that mean nothing.
Where the invoice does not add up
When the totals disagree we name the amount, what the other figures make, and the difference — instead of just “BR-CO-15”. We never change amounts automatically.
Reverse, don’t edit
An invoice that has gone out is not edited but reversed. One click opens it as a credit note (381) or corrected invoice (384), carries every entry across and fills in the reference to the original (BT-25).
CLI, AI agent & desktop
Batch in the terminal, an MCP server for AI agents and a desktop app — the same engine, no server, no JVM.
All of it without installing anything — open an invoice and see straight away what fails.
For businesses
Why businesses choose Beleggo.
Ready for the e-invoicing mandate
Since 2025 businesses must be able to receive e-invoices; sending follows in 2027/2028. Beleggo covers opening, checking, creating and converting — today.
No data egress
Invoices never leave your machine. No cloud, no account, no server. Because no data is transmitted, no data-processing agreement (Art. 28 GDPR) arises — GDPR-friendly by design.
Ready without an IT project
No rollout, no server, no account: opening the page is enough, and the same engine carries on as a desktop app or in the CLI if you want it to. Offline too.
Authority-grade certainty
The same verdict as the official KoSIT validator — the same rule base that also underpins the Service-BW endpoint and the government routers. Guaranteed in CI.
Built for developers
A CLI for batch runs and CI pipelines, an MCP server for AI agents, a desktop app — the same engine as the browser, no JVM, no server hops.
Always current
The rule sets (KoSIT, XRechnung, Peppol) are bundled and automatically monitored against the official sources — nothing silently breaks in the background.
Before and after the invoice
The invoice is not the whole journey.
Beforehand, the master data decides whether a valid invoice can exist at all. Afterwards it has to reach the books, the recipient and the archive. Four terminal commands, all local.
Check master data before the invoice exists
Every other command judges a document. This one judges the partner records documents are built from: who has no electronic address, whose VAT id is invalid, who is filed twice. From an ERP export, from the invoices you already have — or from both, which also shows where the master record and the invoices disagree.
beleggo stammdaten invoices/ --records vendors.csv --profile sap-bpFindings, not clearance: whether a VAT id is actually registered is a confirmation from the tax authority — an online step this deliberately does not take.
Hand over to DATEV
A Belegtransfer package (ZIP with document.xml) for DATEV Unternehmen online, or a real EXTF booking batch with one row per invoice per VAT rate. The consultant and client numbers, fiscal year and account length are asked for, never guessed. The batch stays uncommitted.
beleggo datev invoices/ --format dxso --out documents.zipBoth formats follow DATEV’s published format descriptions and have not yet been verified against a live DATEV import. Import into a test client first.
Transport-ready for Peppol
The validated UBL invoice in its Peppol envelope (SBDH), plus a manifest — exactly what an Access Point accepts for submission. Every header value comes from the document itself; a missing one gets the invoice refused and named rather than quietly filled in.
beleggo peppol-pack invoices/ --out outboundBeleggo is not an Access Point and transmits nothing. The package goes to the service provider you contract with.
Seal a set and prove it
The structured records of a folder as a set in which every entry links over the one before it. Change a document, a field or the ordering and the root changes — a single value you write down. Later the set checks itself and names every discrepancy. Optionally also as a Datenträgerüberlassung in the Beschreibungsstandard.
beleggo archive invoices/ --out holdings-2025Not an archive: the set is what an archive ingests, plus the proof it was checked. Software cannot be certified under GoBD (Rz. 179), and nothing here claims it.
In daily use
Built for professional day-to-day work.
Beyond the single check: reuse invoices, put your own look on the generated PDF and hand validation results out of the house — all local, no account.
- Save, load, duplicate and reuse invoices and templates
- PDF branding: your own logo, accent colour and a payment QR (EPC / GiroCode) scannable with a banking app
- A custom note or payment reference on the generated PDF
- Report export (CSV) for multi-file checks — in the browser and the desktop app
Branding only affects the PDF — the XML’s EN 16931 validity is untouched.
For partners
A test data set with your name on it.
395 e-invoice samples — valid and deliberately defective — each paired with the verdict a conformant validator must reach. The wizard puts your company details in, re-checks every sample and builds the kit in the browser. Eight chapters, explained first and then demonstrated.
The real verdict run over all 395 samples is in the video — nothing sped up.
Integration & customization
Bring Beleggo into your system landscape.
You don't just want to use the checking, creation or conversion — you want it embedded in your ERP, portal or invoicing workflow, or a variant tailored to you? We bring the same engine into your environment and adapt it.
Embed & integrate
Drop the engine into your website, portal or workflow — as a web component, via the CLI or the MCP server. Local, no server hops.
Customize & white-label
Your own branding, tailored validation profiles, additional rules or formats — shaped around your use case.
On-premise & automation
Batch processing, CI pipelines and operation inside your own infrastructure, so invoice data never leaves the building.
Guidance & support
From the first integration to ongoing operation — with a named contact instead of a ticket queue.
Your contact
A person, not a ticket queue.
Questions about e-invoicing, about an integration, or interested in using it in your own organisation? You write directly to the person behind Beleggo — no call centre, no queue.
Still unsure?
Answered quickly, before you start.
Is the verdict reliable?
The same rule base as the official KoSIT validator — cross-checked in our CI.
See conformance →Where does my data go?
Nowhere. Everything runs locally in your browser — no upload, no account, no cloud.
See security →Is it a fit for my case?
Tell us briefly what you have in mind — you get an answer from the person behind Beleggo, not from a ticket system.
Get in touch →Do I even need this yet?
Receiving since 2025, sending from 2027/2028 — depending on turnover. The deadlines guide explains.
See the deadlines →FAQ
What you might still want to know.
How does it actually work?
Validation runs entirely in your browser via Saxon-JS. We read the structured XML (from the PDF for ZUGFeRD) and check it against EN 16931 and the German business rules (BR-DE). Nothing is uploaded — your invoice never leaves your machine.
Do I have to upload my invoice data?
No. Everything runs locally — no upload, no account, no cloud. That is GDPR-friendly by design, because the invoice data never leaves your device — no data-processing agreement arises. Beleggo even works offline.
Is the check as reliable as the official validator?
Yes. Our engine is cross-checked against the official KoSIT test invoices and the official KoSIT validator jar, and returns the same verdict — guaranteed in our CI. It is the same rule base that also underpins the Service-BW endpoint and the government routers.
Which formats are supported?
XRechnung as UBL and CII, ZUGFeRD / Factur-X (XML inside the PDF) and Peppol BIS 3. You can convert between UBL, CII and ZUGFeRD PDF — locally, and re-validated after conversion.
Can I repair invalid invoices?
Yes. The auto-fixer resolves structural errors and value-preserving details (stray whitespace, unescaped characters, a missing date qualifier) in one click — with a before/after diff. The original is kept; amounts, VAT and IBAN are never changed automatically. Anything else you can correct yourself in the editor with live validation.
Is Beleggo GoBD-compliant / an archive?
Beleggo is not an archive. It creates and checks audit-ready e-invoices per EN 16931; the GoBD-compliant, tamper-proof retention (§ 147 AO, typically 8–10 years) is handled by your DMS or archiving system. Export the unchanged original as XML or ZUGFeRD PDF for that. The data stored in your browser (seller profile, customers) is not a substitute for an archive.
How do I make sure the invoice will pass a public authority?
The B2G preflight checks your invoice against the XRechnung rules for public authorities — even if the file started in another format — and lists the mandatory fields still missing. The Leitweg-ID is validated including its check digits.
Is there a way to automate this for developers?
Yes. There is a CLI for batch runs and CI pipelines, plus an MCP server that lets AI agents validate, fix and create invoices — all with the same engine, locally, no JVM.
Can I save invoices and match the PDF to my own look?
Yes. Invoices and templates can be saved, loaded and duplicated in the browser. The generated PDF takes your logo, an accent colour, a payment QR (EPC / GiroCode) and a custom note. Branding only affects the PDF — the XML’s EN 16931 validity is untouched.
What is the difference between ZUGFeRD and XRechnung?
XRechnung is pure XML (the German CIUS of EN 16931); ZUGFeRD / Factur-X is a hybrid: a readable PDF with embedded XML. Beleggo checks and creates both — and for the hybrid it even reconciles the visible page against the embedded XML. See the guides for more.
Keep reading
Comparison
Beleggo compared
Only published, checkable facts — every claim with a source and a date checked.
Error library
Every rule explained
The validation rules in plain language — linked straight from any check result.