KS-eFektywnie
Support
Something not working, or an idea for an improvement? Get in touch — the developer of the app replies personally.
Contact
Email: bartosz@ikolek.pl
The quickest way: in the app, open Settings and tap “Report a problem”. The message automatically includes the app version and the iOS version, which makes it easier to find the cause.
Send an emailFrequently asked questions
How do I connect the app to KSeF?
You need a KSeF token. Generate it in the KSeF Taxpayer Application (ksef.podatki.gov.pl) after signing in for your company’s tax ID (NIP). Then, in the app, open Settings → KSeF connection, paste the token, save it and test the connection.
The app includes a step-by-step guide that shows how to generate the token and connect the app.
When does the app download new invoices?
When you open the app, it downloads new invoices from KSeF by itself if at least an hour has passed since the last sync. You can also pull down the invoice list at any time.
The app also asks iOS for background sync, but the system decides when to run it and it cannot be forced — so it is not guaranteed. It helps to keep Background App Refresh on (iOS Settings → General → Background App Refresh) and not to swipe the app away in the app switcher. Settings → KSeF connection shows when the system last ran background sync.
Does my data go to the developer’s server?
No. The app has no accounts and no developer server. Invoices, payment files and statements are only on your iPhone and — if you have iCloud Drive turned on — in your private iCloud. See the privacy policy for details.
I’m switching phones. What happens to my data?
If you have iCloud Drive turned on, once you sign in with the same Apple Account, the iCloud copy restores the app’s data on your new phone.
The KSeF token never leaves the device, so on the new phone you need to generate it again in the KSeF Taxpayer Application and paste it in Settings.
Which banks does the app work with?
Payment files: Erste Bank, mBank, and the Elixir-0 format for other banks that accept it (including split payment, MPP).
Statements: MT940 (a format offered by most banks), CSV from Erste Bank and VeloBank, and Bank Millennium transaction history (CSV, XLS or HTML; PDF is not supported).
Your bank is missing? Let me know — a sample file (with the data replaced by fictitious values) helps a lot.
Is the app paid?
No. KS-eFektywnie is free, with no ads and no subscription. You can leave a tip to support further development — it doesn’t unlock anything; all features are available from the start.
Can I try the app on the KSeF test environment first?
Yes. In Settings → KSeF connection, choose the test environment. It has separate data and separate tokens — a production token does not work on the test environment and vice versa. Invoices issued on the test environment have no legal effect.
To work with real invoices, switch to the production environment and save a production token.
Is KS-eFektywnie an app of the Polish Ministry of Finance?
No. It is an independent app. “KSeF” is the name of the National e-Invoice System operated by the Ministry of Finance; the app uses its public API.