QuernoUnderstand official mail. Never miss a deadline again.
Take a photo of the letter from the tax office (Finanzamt), your health insurer or an invoice. Querno explains it in your language, calculates the deadline and tells you what to do now.
Understands mail from
From letter to done
No more deciphering officialese, no more keeping deadlines in your head.
Photograph or share
Photograph the letter, even if it has several pages. Or share a PDF or e-invoice straight from your mail or files to Querno.
Understand
What kind of letter is it, what is being asked, how much and by when? Clearly explained, in German or in your language.
Get it done
Deadline with reminder, a ready-made reply or objection, bank transfer via QR code, and a checkmark when it is done.
Querno writes the reply for you
One tap and the letter is ready: with your name, your address, the reference number (Aktenzeichen), the amount and a fully worded justification. All you do is check it and send it off.
- Objection (Einspruch) against a tax assessment or an estimate, with a suspension of enforcement if you wish
- Deferral (Stundung) and payment in instalments when money is tight
- Extension of a deadline, submitting documents later and short replies to authorities, insurers and companies
- Always in German and in official language, even when you use the app in your own language. Querno checks section numbers against the current text of the law
- Send straight from your Gmail, share via your mail app or print as a finished letter
The next step for every letter
Querno sorts out what really matters and offers you the right actions.
- Call with one tap: phone number and contact person taken from the letter
- What is being asked, in plain words and with step-by-step instructions
- Contact details, reference number and bank details from the letter, all copyable
- Mark as done, and the deadline disappears from your list
Paid in seconds, without typos
Querno reads the recipient, IBAN, amount and payment reference (Verwendungszweck) from an invoice, reminder or assessment, and checks the IBAN.
- GiroCode: scan it in your banking app, all fields are already filled in
- Or copy everything with one tap and paste it into the transfer
- E-invoices (XRechnung, ZUGFeRD) with exact values, straight from the file
- Mark as paid, the payment deadline is done, and on the home screen you see what is still open
Every deadline at a glance
Querno calculates deadlines under the Tax Code (Abgabenordnung), including the date of notification, weekends and the public holidays of your federal state. And it shows you how it calculated.
- Reminders well before expiry, even without internet
- Recurring tax deadlines such as VAT advance returns, payroll tax and advance payments, based on your profile
- Home screen widget and an appointment in your iPhone calendar
Answers backed by the law
Just ask: What does this notice mean? Am I still a small business owner (Kleinunternehmer)? How long do I have to keep receipts?
- Querno looks up the current text of the law and names the source
- Attach photos of receipts, dictate questions, ask questions directly about a letter
- General information, not tax advice, and Querno says so too
Everything you need for your mail
From scanning to a finished matter, in one app.
Capture and understand
- Photograph a letter, even with several pages
- Share PDFs and e-invoices from mail and files
- Type, sender, amount and deadline recognised automatically
- Simple explanation in 15 languages
- What is being asked and the next steps
Write and reply
- Objection with suspension of enforcement
- Deferral and payment in instalments
- Deadline extension and submitting documents later
- Replies to authorities, insurers and companies
- Send via Gmail or your mail app, PDF for printing
Pay
- GiroCode for every banking app
- IBAN check and payment reference
- Copy everything with one tap
- Mark as paid
- Open amounts at a glance
Deadlines
- Calculation under the Tax Code, including public holidays
- Reminders and push notifications
- Recurring tax dates from your profile
- Widget for the home screen
- Appointment in the iPhone calendar
Order
- Sorted automatically: tax office, health insurer, invoices …
- Search by sender, amount or reference number
- Cases: invoice, reminder, debt collection together
- Warning when a matter escalates
- Done and paid at a glance
Questions and answers
- Chat about taxes, health insurance and authorities
- Backed by current legal texts, with source
- Attach photos and dictate questions
- Questions directly about a letter
- History of all conversations
For the self-employed
- Small business watchdog for the turnover limits
- Tax profile: legal form, VAT, employees
- Company details as sender in every letter
- Business: team with roles and shared mail
- Receive and read e-invoices
Secure and convenient
- App lock with Face ID
- Sign in with Apple, Google or email
- Your letters on all your devices
- Light, dark or automatic
- Delete everything at any time
German mail, explained in your language
The explanation comes in your language, while Querno writes replies to authorities in German.
Start small, cancel any time
Subscriptions are billed through your Apple ID and can be cancelled monthly.
Free
- 2 letters a month
- 2 questions a month
- Deadlines and reminders
Plus
- 10 letters a month
- 20 questions a month
- Drafts and sending by email
Pro
- 30 letters a month
- 100 questions a month
- Everything in Plus
Business
- 100 letters a month
- 300 questions a month
- Team with roles
Your mail stays your business
Querno is built for letters that are nobody else's concern. That is why we are exact about what happens to your data.
- On your iPhone. Letters, deadlines and profile live in the app. Without an account, only the photo leaves your device for analysis.
- Photos are not stored permanently on the server. For analysis they travel encrypted through our server in Frankfurt to the AI and are not stored permanently.
- Account is optional. With an account, your data is stored in Frankfurt and visible only to you. You can delete everything at any time.
- No training on your data. The AI analysis is carried out on our behalf and is not used for training.
Frequently asked questions
Does Querno replace a tax advisor?
No. Querno explains letters, rules and deadlines and helps you get things done. For binding information in your individual case, turn to a tax advisor or the authority. Querno tells you when a question belongs there.
Which letters does Querno understand?
Mail from the tax office such as tax assessments, estimates, payment reminders and queries, as well as letters from health insurers, pension insurance, the job center, the family benefits office, cities and municipalities, plus invoices, payment reminders and e-invoices.
How accurate are the deadlines?
Querno calculates according to the rules of the Tax Code (Abgabenordnung), with notification four days after posting, weekends and the public holidays of your federal state. For every deadline you can see how it was calculated. The actual date of receipt remains decisive.
What is an e-invoice and do I need it?
Since 2025, all businesses in Germany must be able to receive e-invoices, including small business owners. These are XML files (XRechnung) or PDFs with embedded data (ZUGFeRD). Querno opens both and takes over the amount, IBAN and due date exactly.
Is Querno available for Android?
Querno is available for iPhone first. The Android version is in preparation.
How do I cancel a subscription?
At any time in your iPhone settings under your name › Subscriptions. The subscription runs until the end of the paid month.
Querno provides general information and does not replace tax or legal advice within the meaning of the German Tax Advisory Act (Steuerberatungsgesetz).
Never dread the mailbox again
Download Querno and try it with your next letter. The first two letters each month are free.
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