Offline invoicing with e-invoices, no subscription
App + Excel · 5 languages included (English, German, Bosnian, Serbian, Croatian) · instant download · one-time purchase
Many freelancers and small businesses still write invoices in Word or Excel – and only notice the missing service date, a typo in the IBAN or a forgotten VAT note when the client calls back. On top of that comes e-invoicing: in Germany, businesses have had to be able to receive e-invoices since 2025. From 1 January 2027, companies with more than €800,000 turnover in the previous year must issue e-invoices to other German businesses, and from 2028 this applies to nearly everyone. Exceptions apply, among others, to small businesses under § 19 UStG and to small invoices up to €250.
The ProPraxisPlan Invoice Studio takes the routine off your hands: enter the client and the line items, the app does the maths, checks the mandatory details and creates the e-invoice if you need one.
Buy once. Work offline. No monthly fee. 60-day money-back guarantee.
Then a one-time €59 (final price incl. VAT) · no subscription · 60-day money-back guarantee
What the Invoice Studio does for you
- Invoices and quotes in minutes: pick or type a client, add items from your own service list – totals, tax rates, discounts and down payments are calculated for you.
- Invoice check: shows live what is missing – service date, tax number, address, IBAN typos, the small-business VAT note (§ 19 UStG) or the VAT ID for reverse charge. “Fix” takes you straight to the field.
- E-invoice in one click: ZUGFeRD PDF and XRechnung (XML) according to EN 16931. We checked our files with the Mustang validator.
- Clean numbering: sequential with no gaps. Finalised invoices are locked; corrections are made with a credit note, so your invoice sequence stays traceable.
- Payments and reminders: record incoming payments, create a payment reminder or dunning letter as PDF or text.
- Quotes: track their status and turn a quote into an invoice with one click.
- Read e-invoices you receive: open an XRechnung or ZUGFeRD file, check totals and IBAN, keep the due date in view.
- Overview: open, overdue, paid, a “Next steps” list and a rough quarterly VAT preview.
- Professional look: 3 templates, your colour, your logo, payment QR code (GiroCode) for banking apps.
Who it is for – and who it is not for
A good fit for freelancers, tradespeople, service providers and small businesses who want to write correct invoices simply and safely – including small businesses exempt from VAT.
Not a fit if you need full bookkeeping with bank connection, payroll or a DATEV interface.
The e-invoice formats (ZUGFeRD, XRechnung) follow the German and European standard EN 16931. The app itself works for invoices in any of its 5 languages; please check the invoicing rules of your own country.
In every ProPraxisPlan tool
- Runs on computer, iPhone, iPad and Android – on your phone or tablet, open your app link and add it to your home screen; it then works like an app, offline too. No installation.
- Excel file with overview and charts, optionally synced automatically in Chrome/Edge
- Share securely by QR code with your team or tax adviser: you decide role, password, validity and whether changes are allowed
- 5 languages: English, German, Bosnian, Serbian, Croatian – the invoice itself too
- Dark and light design, sample data to try it out
Video: how the Invoice Studio works
The video guide shows the app step by step, from activation to daily use (3:08 min, German). The download includes the video guide in all 5 languages.
What you get (instant download, ZIP)
- Invoice Studio as an HTML app in 5 languages
- Excel workbook in 5 languages
- PDF guide in 5 languages (with your app link for phone and tablet)
- Video guide (all 5 languages)
Activate and get started
- Activate once: on first start, enter your name and your activation number from the thank-you page or your order email. This needs a short internet connection once.
- 1 purchase = 1 main device. Team members and further devices are added by QR code. New device? Sign out the old one in the settings and activate the new one.
- About once a month the app briefly confirms your licence when you are online. Only the number is checked – your data stays on your device.
On a phone or tablet? Open app.propraxisplan.de/invoice/ and tap “Add to Home Screen”. Activate with your activation number from the thank-you page or the order email.
Frequently asked questions
Do I need technical skills?
No. You type text and numbers and click buttons. There are no formulas or code.
When do I have to issue e-invoices?
For invoices to other businesses in Germany: from 2027 if your previous year's turnover was above €800,000, from 2028 basically for everyone. You must be able to receive e-invoices since 2025. Invoices to private customers are not affected. As of October 2026 – please check your case with your tax adviser.
Can I import my client list?
Yes, from Excel or CSV. You see beforehand which column is which, and only “Import” saves it.
What if I make a typo?
Drafts can be edited freely. Finalised invoices are corrected with “Correct” (credit note + new invoice). Deleted items can be restored with “Undo”.
Where is my data?
Only in your browser on your device. The app reminds you to save a backup regularly.
Where do I find the activation number?
In your order email under “activation number” (it is also shown on the thank-you page). Enter it together with your name on first start – that is your personal activation key.
Do I need the internet?
Only briefly: once to activate, about once a month for the licence check, and for secure sharing. Everything else works offline.
What if I change my computer or phone?
Save a backup in the app, sign out the old device in the settings and activate the new one with the same number. Then load the backup – everything is back.
Do I need Excel?
Not for the app, it runs in the browser. You open the included Excel file with Microsoft Excel or a compatible program.
May I use the app in my business?
Yes. The licence covers you and your own business; you add your team by QR code. Passing it on or reselling it is not allowed.
Are there extra costs?
No. Buy once, no subscription.
Good to know
- 60-day money-back guarantee: if the app does not suit you, you get the full price back within 60 days of purchase, without lengthy explanations. Write to Digistore24 (link in your order email) or to info@propraxisplan.de. The activation of your order is then deactivated. This voluntary guarantee applies in addition to your statutory rights.
- Digital product – nothing is shipped. You get the download right after purchase on the thank-you page and by email.
- When sharing securely, the data is encrypted on your device first.
- Personal licence for you and your business; passing it on or reselling it is not allowed.
- No tax or legal advice. You are responsible for tax rates and exemptions.
Made by ProPraxisPlan
How you get the app
Right after ordering, the thank-you page shows the download (ZIP file) and your activation number. You also receive both by email. Nothing is shipped – the product is a pure download.
Order and payment
Order and payment are handled by our sales partner Digistore24, which sells the product as a reseller. You pay securely by PayPal, credit card, Klarna, Apple Pay, Google Pay or bank transfer – depending on your country.
Try it free for 7 days, then a one-time €59 (final price incl. VAT). You only pay after the trial period. Many comparable programs are only available as a monthly subscription – here you pay once, with no follow-up costs.
Then a one-time €59 (final price incl. VAT) · no subscription · 60-day money-back guarantee
Manufacturer and provider of the product: ProPraxisPlan, Esmir Kasumovic · Legal notice · Privacy policy · Questions? info@propraxisplan.de