KSeF Viewer is an iPhone and iPad app for browsing, analysing and issuing invoices in Poland’s National e-Invoicing System (KSeF). See all features →
Contact
Have a question, a problem or an idea for a new feature? Write to kontakt@psw-it.pl — we usually reply within 1–2 business days.
When reporting a bug, include your device model, iOS version and app version, and briefly describe what happened. A screenshot helps a lot — hide any data you don’t want to share. Never send your token, certificate or password.
Frequently asked questions
What do I need to connect the app to KSeF?
Your company’s tax ID (NIP) and a KSeF token or certificate with permission to view invoices (and to issue them, if you want to issue invoices). You can generate them in the KSeF Taxpayer Application (ksef.podatki.gov.pl). If an accounting firm handles your books, they can grant you the right permissions.
Token or certificate?
KSeF tokens only work until 31 December 2026. From 2027, signing in to KSeF is possible only with a certificate. You can generate an “authentication” certificate in the KSeF Taxpayer Application and load it into KSeF Viewer as a .p12 or .pfx file.
Can I try the app without signing in?
Yes. On the first screen choose “Wypróbuj bez logowania” (try without signing in) — demo mode shows sample invoices and every feature, without sending anything to KSeF.
Do my invoices go to your servers?
No. We have no servers and no user accounts. The app connects directly to the Ministry of Finance’s KSeF and stores data only on your device. Details in the privacy policy.
How do I add a second company?
On the invoice list, tap the company name at the top of the screen and choose “Dodaj firmę” (add company) — a PRO feature. Each company has its own invoices, analytics and seller details; switch between them with the same button.
The app shows no invoices or reports a connection error
Check your internet connection and whether your token or certificate is still valid and has permission to view invoices. The error may also be caused by a KSeF outage — the Ministry of Finance posts notices at ksef.podatki.gov.pl. If the problem persists, write to us.
How much is PRO and how do I cancel it?
PRO is a monthly or yearly subscription with a one-week free trial — current prices are shown in the app before you buy. Subscriptions are managed by Apple: iPhone Settings → your name → Subscriptions → KSeF Viewer. Cancel at least 24 hours before the end of the period so it does not renew.
How do I restore PRO on a new device?
Sign in with the same Apple ID you used to buy the subscription and open the PRO screen in the app — the subscription will be recognised. If needed, use the restore purchases button on that screen.
How do I get a refund?
Payments and refunds are handled only by Apple — request one at reportaproblem.apple.com.
How do I delete my data from the app?
In the app choose Settings → “Wyloguj” (sign out), which removes credentials and invoices from the device, or simply delete the app. Invoices in KSeF are not affected.
Documents
Publisher
PSW-IT Piotr SucheckiNIP 5223111437, REGON 369313204
e-mail: kontakt@psw-it.pl
KSeF Viewer is an independent app and is not affiliated with the Polish Ministry of Finance.