Mindeststeuer App Incident History

Our hosting service provider informed us about planned maintenance of the core networking infrastructure to improve performance and scalability in our data center in Frankfurt. We expect minimal impact. The maintenance will be performed during the night hours. The maintenance will be performed in three phases as outlined below: July 20, 22:00 to July 21, 00:00 UTC July 21, 22:00 to July 22, 00:00 UTC July 22, 22:00 to July 23, 00:00 UTC

Maintenance ended

Our hosting service provider informed us about planned maintenance of the core networking infrastructure to improve performance and scalability in our data center in Frankfurt. We expect minimal impact. The maintenance will be performed during the night hours. The maintenance will be performed in three phases as outlined below: July 20, 22:00 to July 21, 00:00 UTC July 21, 22:00 to July 22, 00:00 UTC July 22, 22:00 to July 23, 00:00 UTC

Maintenance ended

Our hosting service provider informed us about planned maintenance of the core networking infrastructure to improve performance and scalability in our data center in Frankfurt. We expect minimal impact. The maintenance will be performed during the night hours. The maintenance will be performed in three phases as outlined below: July 20, 22:00 to July 21, 00:00 UTC July 21, 22:00 to July 22, 00:00 UTC July 22, 22:00 to July 23, 00:00 UTC

BZSt removed the orange warning banner on online.portal.bzst.de on July 15th, 2026 at around 14:00 CEST. Currently, we and our clients don't observe any issues related to online.portal.bzst.de or DIP production. Multiple clients are still awaiting protocols for their submissions (both via DIP API and manual XML upload). We assume that now the issues have been resolved, protocols will be processed and delivered soon. We are marking the incident as resolved.

online.portal.bzst.de returned 503 Service Unavailable around 14:00 CEST on July 14th, 2026

BZSt replaced the text in the [warning banner](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870), on Tuesday, July 14th, 2026 at around 13:00 CEST stating: > Derzeit steht die Anmeldefunktion und die Vorgangsübersicht nur eingeschränkt zur Verfügung. Die Kundentestumgebung ist ebenfalls derzeit nicht errreichbar. and dated it back to June 25th, 2026. The BZSt online.portal seems generally available. We don't observe any issues related to login, or token generation. We can confirm, that the list of transactions (German: Vorgänge) does not work as expected. It seems the text in the warning banner is a delayed reaction to the issues we observed yesterday. (Typos in warning are originally from BZSt.)

DIP production does not return errors anymore since July 13th, 2026 at around 14:00 CEST. We mark the incident concerning DIP production as resolved. BZSt online.portal still contains a warning banner. We can't observe any issues while login. As long as the warning banner is published we leave the service marked as degraded.

DIP production is not available and returns errors: - 500 Internal Server Error (HTML Body) - 400 Invalid token audience (JSON Body)

BZSt replaced the dedicated maintenance page with a [warning banner](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870), on Monday, July 13th, 2026 at around 10:30am CEST stating: > Aufgrund wann Wartungsarbeiten kann es bei der Anmeldung zu kurzen Unterbrechungen kommen. and dated it back to June 25th, 2026. The BZSt online.portal seems generally available. In some cases the login is not possible. (Typos in warning are originally from BZSt.)

BZSt disabled DIP production and online.portal.bzst.de on July 13th, 2026 at 8:20am CEST and published at 9:15am CEST the notice, that they perform (unannouned) maintenance approximately till 14:00 CEST. We asked the BZSt why the maintenance was not announced earlier.

BZSt wrote us (on July 15th, 2026 at 13:24 CEST): > die KTST sollt jetzt wieder funktionieren. (Typos in message are originally from BZSt.) We don't observe any errors on DIP test since July 15th, 2026, as of 10:00 am, and therefore mark this incident as resolved.

BZSt answered (on July 15th, 2026 at 9:56am CEST): > Derzeit steht die KTST aufgrund von technischen Gründen nicht zur Verfügung; auf dem BZSt online.portal kann es ebenfalls zu Einschränkungen kommen. > Das BZSt arbeitet an der Fehlerbehebung; ein genauer Zeitpunkt wann die Fehler voraussichtlich behoben sind, kann derzeit nicht benannt werden. > Ein entsprechender Hinweis wurde auf dem BZSt online.portal geschaltet. We don't observe any errors on DIP test since July 16th, 2026, as of 10:00 am, but we leave DIP test and DIP messages (test) services marked as degraded for today, as we expect further unannounced downtimes based on the BZSt answer.

BZSt acknowledged our newest incident report on July 15th, 2026 at 8:21 CEST. We observe currently errors 501 Internal Server Error (on token creation) and 401 Unauthorized (for other endpoints).

DIP test returns 500 Internal Server Error for about 50% of the requests on the token creation enpdoint as of July 15th, 2026 around 8:00am CEST. We are marking the service as degraded. We received an email on July 15th, 2026 at 8:01am CEST from BZSt stating: > Der IT-Dienstleister teilte uns mit, dass die KTST wieder zur Verfügung steht. This response concerned our earlier [incident report](https://status.mindeststeuer.app/de/incident/961979) which we send out to BZSt on July 13th, 2026. We reported this incident to BZSt.

DIP test returns 500 Internal Server Error on token creation enpdoint as of July 14th, 2026 around 22:00 CEST. Therefore submitting XML and retrieval of data is currently not possible.

We received an email on July 15th, 2026 at 8:01am CEST from BZSt stating: > Der IT-Dienstleister teilte uns mit, dass die KTST wieder zur Verfügung steht. This response concerns our incident report which we send out to BZSt on July 13th, 2026. As of July 14th, 2026 around 22:00 CEST there is [another incident](https://status.mindeststeuer.app/de/incident/964457) on DIP test.

DIP test is fully functional now. BZSt published a new warning banner, on Tuesday, July 14th, 2026 at around 13:00 CEST (on the BZSt online.portal, and not ktst.bzst.de) stating: > Die Kundentestumgebung ist ebenfalls derzeit nicht errreichbar. and dated it back to June 25th, 2026. We observe the opposite. Since July 14th, 2026 at around 13:00 CEST the DIP test is fully functional. It seems this is a delayed response to the incident we encountered and reported in the last 28 hours. (Typos in warning are originally from BZSt.)

BZSt removed the warning banner from ktst.bund.de We still observe errors (especially 500 Internal Server Error) while requesting tokens. The error is currently returned for about 50% of the requests. Therefore we are marking the service as degraded.

DIP test is currently not available returning error 400 (Invalid token audience) on token creation. We won't inform BZSt about this incident due to the current warning banner on https://ktst.bzst.de

BZSt published on Monday, July 13th, 2026 at around 9:00am CEST a warning banner stating: > Unsere Kundentestumgebung steht vorübergehend aufgrund von Wartungsarbeiten nicht zur Verfügung. and dated it back to June 3rd, 2026 (over one month ago). DIP test accepted data since July 9th, 2026 ~16:30 CEST without errors. We assume this a warning concerning downtime of DIP test in near future, as DIP production is currently not available. We are marking DIP test degraded as a precaution.

DIP test is functional again since July 9th, 2026 ~16:30 CEST. We didn't receive any additional information from BZSt yet. The warning banner from the main BZSt online.portal page was removed around the same time.

BZSt answered: > Ein entsprechender Hinweis, dass die KTST aktuell nicht zur Verfügung steht wurde auf dem Portal veröffentlicht. Derzeit kann noch keine Aussage darüber getroffen werden, wann die KTST wieder zur Verfügung steht. We assume, that BZSt means with "entsprechender Hinweis" the [general warning](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870) changed on Monday, July 6th, 2026 and dated back to June 25th, 2026, with the text: "Derzeit steht die Massendatenschnittstelle nur eingeschränkt zur Verfügung." We asked an additional claryfing question.

The DIP test environment still returns a 404 error on multiple endpoints (when authenticated with a token). Therefore it is not possible neither to submit, nor retrieve test data. We don't observe any SSL connect errors since July 8th, 2026 23:52 CEST.

The DIP test environment returns a 404 error on multiple endpoints i. a. /dip/md/v2_1/start/PILLAR_II (when authenticated with a token). Therefore it is not possible to start the submission process for test purposes, nor retrieve data. We receive SSL connect errors (randomly) as well.

BZSt removed the warning banner from the main page of BZSt online.portal on July 9th, 2026 at around 17:00 CEST. We are marking incident as resolved, while we await feedback from our clients.

Our clients report, that in some cases the manually uploaded XML transactions (German: Vorgänge) are still not visible. While some of our clients report emails received with protocol notifications and (partial) visibility of the transactions in the BZSt online.portal.

Our clients report, that for manual XML uploads done in the BZSt online.portal, the transactions (German: Vorgänge), are not accessible after upload in the portal. The links sent by the BZSt as notifications/confirmations are not functional. Moreover, no protocols are being provided (neither for correct nor for invalid filings) for manual XML uploads. It seems, that the [current incident report](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870), stating "few rare cases" is not accurate. In our perspective all transactions (Vorgänge) for XML uploads are not accessible in the BZSt online.portal.

BZSt [published a statement](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870), that missing messages in the portal are a "rare case".

BZSt [published a statement](https://www.bzst.de/SharedDocs/Kurzmeldungen/DE/2026_Kurzmeldungen/06_Juni/20260617_technische_probleme_bzst_online.portal.html), that there is currently an incident with https://online.portal.bzst.de. Access to protocols and messages for uploaded data is not possible.

BZSt removed the warning banner from the main page of BZSt online.portal on July 9th, 2026 at around 17:00 CEST. The issue concerning XML transmission timeouts of complex XML datasets to DIP production is still present. We still await a response from BZSt.

BZSt extended the warning on the main page on Monday, July 6th, 2026 at 10:00 am with the information, that the DIP production is currently available only to a limited extent. The [dedicated warning subpage](https://online.portal.bzst.de/SharedDocs/Warnmeldungen/DE/warnung_wartungsarbeitenKW25.html?nn=23870) is dated June 25th, 2026. To the best of our knowledge the warning concerns the XML transmission timeouts of the DIP production. We observe a change in returned server response (from 502 to 408) for complex XML data sets. The status code 408 blames the sending side for not sending data in time. This is an incorrect and obscure technical claim from the BZSt side. We reported this incident to BZSt as well.

Our clients encounter timeouts and 502 server errors on complex Pillar-II-XML datasets being sent via the DIP production API. (The same XML datasets are processed without any errors in DIP test API.) Simple XML datasets are processed correctly in DIP production. We recommend currently the manual XML upload in the BZSt online.portal, in such cases. We reported those cases to BZSt and await a response.

We don't observe any SSL connect errors since July 8th, 2026 23:52 CEST. Marking incident as resolved.

Our monitors report SSL connect errors. On the other hand opening the website in the browser loads the content without issues. We are investigating the root cause. We assume this might be an issue at the intermediary security layers.