Invoicing that
runs itself.
Compliant invoices, quotes, automatic payment reminders — and an AI assistant that understands your numbers and does the work.
No card required · 10 invoices/mo free
Billtree is ready for everyone
Every business is different — the flow stays just as simple.
Solo founders & freelancers
Quote, invoice, reminder — pro results solo, in minutes.
Kleinunternehmer
VAT-free invoicing with the §6 clause — automatic, error-proof.
SMEs & merchants
Product catalog, delivery notes, recurring invoices, multi-currency.
Accountants
Invited access, ebInterface XML export, clean data.
Webshops & developers
REST API, signed webhooks — invoices flow from orders automatically.
Three steps to your first invoice
Sign up free
E-mail + password and you're in. Enter company data once.
Customer + items
The UID fills in everything. Pull items from your catalog.
Issue → paid
German PDF, e-mail, QR payment — reminders run themselves.
See it in action
Invoicing that doesn't hurt
Customer lookup with the EU company registry — type a name or UID and everything fills in. Gapless numbering, German PDFs, e-mail with one switch.
- VIES + registry lookup
- 20/13/10% VAT or Kleinunternehmer
- EUR, HUF, USD, CHF, GBP
Your clients will love paying you
Every invoice gets a public page: PDF, bank details and an EPC QR — clients pay from their banking app in seconds. Quotes are accepted with one click.
- EPC QR: George, Raiffeisen, N26…
- Online quote acceptance
- Automatic “paid” marking
An assistant that actually works
Not a chatbot with canned answers. It knows your entire database, queries freely, issues invoices, sends e-mails — you just ask.
And that's far from all
AI assistant
Free-form queries + real actions, safely scoped.
Appointment booking
Booking page + embeddable widget, with calendar — optionally invoiced.
Compliant invoices
Gapless numbers, UStG, German PDFs — audit-proof.
Auto reminders
Polite 1st reminder, then levels 2–3 — automatically.
Quote → invoice
Online acceptance, one-click conversion.
Recurring invoices
Monthly retainers issued & sent — while you sleep.
AI receipt scanner
Photo → vendor, amount, VAT, category. Done.
e-invoice + delivery note
ebInterface XML for B2G, delivery notes in one click.
Team & accountant
E-mail invites with roles — your accountant included.
Your office, in your pocket
Billtree is an installable web app (PWA): launch it from your home screen and it runs like a native app — full feature set included.
- Invoice on the go — quotes and invoices on site
- Snap a receipt: the AI reads and records it
- The AI assistant in your pocket, anywhere
Install: Chrome → “Add to home screen” · iPhone: Share → “Add”
For developers: an API you'll enjoy
REST API with key auth, HMAC-signed webhooks, e-invoice XML. Your webshop issues an invoice with one call — and gets notified when it's paid.
POST /api/v1/invoices Authorization: Bearer bil_live_… { "customer": { "name": "Muster GmbH" }, "items": [{ "description": "Beratung", "quantity": 5, "unitPrice": 120 }], "issue": true } → 201 { "number": "RE-2026-0031", "publicUrl": "…" }
Pay with anything, connect to anything
Your customers pay via Stripe — card, Apple Pay, Google Pay, EPS, SEPA. E-invoicing (Peppol), DATEV export and the REST API are built in too.
Card / EPS / SEPA payments run via Stripe; automation via the open REST API and webhooks.
Simple, honest pricing
Basic
- 10 invoices / month
- Unlimited customers & products
- PDF, e-mail, payment link + QR
- Expense tracking
Pro
- Unlimited invoices & quotes
- AI assistant + receipt scanner
- Auto reminders + recurring invoices
- API, webhooks, e-invoice XML
- Team & accountant access
No card to sign up · Cancel anytime · Your data on EU servers (Frankfurt)
Refer a friend — you both get 1 month of Pro for free
Every Billtree account comes with a personal referral link. When your invitee subscribes to Pro, you both get +1 month of Pro — every subscribing referral earns another free month.
Fresh from the blog
Tax, invoicing, receivables — knowledge for Austrian businesses.
FAQ
Yes — mandatory UStG invoice elements, gapless numbering, 20/13/10% VAT and the Kleinunternehmer exemption are built in. Issued invoices are immutable; only cancellation is possible.
Invoices are always issued in German (the safe choice in Austria) — the app itself is available in Hungarian, German and English.
The E-Rechnung is a structured, machine-readable e-invoice. It is mandatory for public-sector (B2G) clients in Austria. Billtree exports both ebInterface 6.1 and Peppol BIS 3.0 (UBL, EN 16931), and prepares you for the upcoming EU ViDA B2B mandate.
No drama: your data stays intact; you just need Pro to issue more. Basic is free forever (no expiring trial); annual Pro gives you 2 months free. Cancellable anytime in two clicks.
Your data is stored on EU servers (Frankfurt) under EU privacy rules over encrypted connections. The AI only sees your own company's data and is architecturally blocked from sensitive fields.
Yes — load customers and products via the API in seconds, and set the invoice sequence to continue exactly where your old tool left off.