The matu.sk app is used for photographing accounting documents and sending them into the bookkeeping, for an overview of bank payments, for the mileage log, and for keeping in touch with the accountant. This page explains what the app processes, where it sends it, and how it is protected.
In effect from 9 September 2026
matu.sk, Sabinovská 5, 821 03 Bratislava
IČO: 50 756 893
E-mail: uctovnictvo@matu.sk
The app is not a public service. It is used by the matu.sk accounting office and its clients, who receive login details from it. Without an account on the office’s server, you cannot sign in to the app or do anything in it.
For data found on clients’ documents, matu.sk acts as a processor — it processes it for the client and on the client’s instructions, under a data processing agreement. For the app user’s own login details, it acts as a controller.
A photo or PDF of the document and the data the app reads from it: supplier and customer, IČO, tax ID and VAT ID, dates, document number, variable symbol, account number, amounts and the VAT breakdown, individual line items and the full text that could be read from the document. A document may also carry personal data — for example a sole trader’s name or address. The app handles the document as it arrives; it deletes nothing from it.
If bank access has been set up for the company, or a statement is loaded into the app, the date, amount, currency, variable symbol, the counterparty's name and account number are processed. This serves one purpose: to match a payment with a document and show which document a payment is still missing for.
Your login name and password for the office's server. The password is kept exclusively in the phone's secure storage (Keychain) and is released only after verification by face, fingerprint or device passcode. It never leaves the device except to the office's server, at the moment you sign in.
The device's location, even when the app is not on screen. The course of the route is recorded — coordinates, time, speed and distance travelled — and each trip also includes the vehicle's registration number and details, the driver's name, the purpose of the trip, the start and end points, stops, costs and meal allowances. The mileage log is a mandatory record under tax law, and it cannot be kept without recording the route.
Location is tracked only while a trip is running. A trip is started manually, by tapping a tag in the car or by connecting to the car; once it has ended, the app no longer tracks location. While it runs, iOS shows a blue indicator in the status bar.
The text of questions and answers, and any attached image. These pass through the office’s server and stay with the document or payment they relate to. If the app receives a voice call from a website visitor, the call audio passes through it; the call is recorded on the visitor’s side and transcribed into text so a written record remains — the audio itself is deleted once the transcript is made. The microphone turns on only once you answer the call.
If you allow notifications, the identifier Apple assigns to the app (device token) is saved on the office's server. It serves one purpose only — to let you know a question has come in or something has finished. It does not contain your name or phone number.
In the app, the accountant also sees payroll and levies, tax account balances and the preliminary VAT of her clients. This data is not created in the app — it is loaded from the office's server and gives an overview of what needs to be paid.
Choices you make in the app — the open month, the selected company, appearance, how files are named, reminders. These stay on the phone.
The app keeps an internal log of its own operation — times, error messages, file and company names. It is used to find the cause when the app gets stuck. It is sent only when you tap "Send debug to NAS" in Settings, and it goes to the same server as the documents, nowhere else. It can be deleted from the same place.
The app communicates only with the services listed below. All communication is encrypted (HTTPS), and the app has no exception that would let the encryption be bypassed. All parties except Apple are based in the European Union. Apple is a US company, and this involves system services of the phone itself (notifications and maps); the transfer relies on the European Commission's adequacy decision on data protection in the US.
| Where | What goes there | Why |
|---|---|---|
| matu.sk server (Synology NAS, Slovakia) |
The document as a PDF, the data read from it, the month’s list of documents, the login name; the debug log on request | This is the office's own accounting storage. The document belongs there, and without it the app would serve no purpose. |
| matu.sk map server (Slovakia) |
Points of the recorded route | Smoothing the route to follow the shape of real roads so it can be read on the map. It is the same office server, not an outside service. |
| Apple (notifications and maps) |
Device identifier and the notification text; when completing an address for a trip, the coordinates and the searched place name | Only Apple can deliver notifications to the phone. The map and place names are a system feature of the phone. |
| Open-Meteo (Germany) |
Coordinates of the starting point and the date of the trip | The weather that was on the route that day. Nothing is sent that could identify a person or a vehicle. |
| Overpass API (Germany, OpenStreetMap) |
Coordinates of a section of the route | Finding out whether the trip went along a motorway or through a town — used to calculate fuel consumption and driving pace. |
| stkonline.sk (Slovakia) |
The vehicle registration number you enter yourself | Adding the VIN, make, model and the roadworthiness and emissions test dates from the public vehicle register. This happens only when you tap for it. |
| Register of Legal Entities (Statistical Office of the Slovak Republic) |
The IČO from the document | Adding the name and registered address of the company that issued the document. |
| eKasa of the Slovak Financial Administration | The identifier from the QR code on the cash receipt | Verifying the receipt directly with the tax authority. It returns the exact amounts and items, so we don't have to rely on reading them from a photo. It is sent only when the document has a QR code. |
| Register of Financial Statements of the Slovak Republic | The IČO from the document | Adding the name and tax ID of the company that issued the document. |
| VIES (European Commission) | The VAT ID from the document | Verifying whether the VAT ID is valid. |
| National Bank of Slovakia | Nothing — just the date | Downloading the exchange rate table for documents in a foreign currency. No personal data leaves in the process. |
| FIO banka (Czech Republic) |
The read-only token you enter yourself | Downloading the company’s bank statement. Without an entered token it does not connect at all. The token is read-only — it cannot be used to make a payment. |
The matu.sk server is physically located in the Slovak Republic and is managed exclusively by the accounting office. It is not a third-party cloud.
Data from documents is processed because it is required by the Accounting Act and tax regulations, and to perform the bookkeeping contract — Article 6(1)(b) and (c) GDPR. Login details are processed to perform the contract and to secure access, Article 6(1)(b) and (f) GDPR.
Providing the data isn't voluntary in the sense that without a document there is nothing to book; the app is just one of the ways to get a document into the accounts.
You have the right to access your data, to have it corrected or deleted, to restrict its processing, to data portability, and the right to object. You can exercise these rights at uctovnictvo@matu.sk.
The right to erasure does not apply to documents the office is legally required to keep under the Accounting Act — those can only be deleted once the statutory retention period has passed.
You can file a complaint with the Slovak Data Protection Authority (Úrad na ochranu osobných údajov SR), dataprotection.gov.sk.
The app is a work tool for bookkeeping and is not intended for anyone under 16. Children’s data is not deliberately processed.
Whenever something changes in the app that affects your data, this page changes too, along with the date at the top. The office notifies users directly of any significant changes.
If anything in the app does not work, or you do not understand something, get in touch with the office:
E-mail: uctovnictvo@matu.sk
Phone: +421 904 343 950
Working days 8:00 – 17:00
Closing your account. Access to the app is set up by the office, so the office closes it too. Write to uctovnictvo@matu.sk and we will close the account. What happens to the data, and which documents have to be kept by law, is covered in sections 06 and 08 above.
Who publishes the app. The matu.sk mobile app is published by ACC-NET s.r.o., co-owner of matu.sk, IČO: 51 482 711, Sabinovská 362/5, 821 03 Bratislava. Data in the app is processed by the matu.sk accounting office as described in section 01.
We process the conversation and the data you enter in line with our privacy policy. We send the chat transcript to the accountant and, once you confirm your address, to you as well.