MiKaDiv FM reports must add timezone offsets and fixed ID fallbacks

Credit institutions obliged to withhold capital-income tax under §§ 43 ff. Einkommensteuergesetz, paying agents, custodians, certified financial intermediaries, reporting entities and their service providers transmitting MiKaDiv FM XML reports under § 45b (excluding paragraph 9) and § 45c Einkommensteuergesetz through the DIP target procedure MIKADIVFMBzst must apply binding transmission content for the timestamp, person identifiers and message attachmentsBzst.

Every independent report carries a fachlicher Zeitstempel that orders correction, cancellation and supplement chains: follow-up reports reference the initial report through the ErstmeldungUUID, and the timestamp fixes the chronological position of each report in the lifecycle from initial report to cancellation. The timestamp must be transmitted with a mandatory timezone offset in local time (Europe/Berlin)Bzst: +01:00 for winter timeBzst and +02:00 for summer timeBzst, for example 2027-06-02T08:47:14+02:00 and 2027-11-02T08:47:14+01:00. The explicit offset avoids errors at the summer/winter time change. A correction, cancellation or supplement whose referenced initial report has not yet been processed waits up to ten daysBzst; if no report with an older timestamp arrives within that window, the waiting report is finally rejected with general return code 03Bzst. A new general return code 09, titled Format bei Zeitstempel ungültigBzst, rejects a message or report whose date-and-time format for the timestamp is invalidBzst.

For a non-natural person, the German business identification number under § 139c Abgabenordnung (Wirtschafts-Identifikationsnummer, W-IdNr) must be stated when it is knownBzst. The basic number under § 139c (1) Abgabenordnung is supplemented with the distinguishing feature under § 139c (5a) Abgabenordnung using "00001"Bzst, uniformly and without legal effect. When the W-IdNr is not known but the German Steuernummer is available, the Steuernummer is the decisive identifier for the transmissionBzst. For a creditor with limited tax liability for whom neither the W-IdNr nor the German Steuernummer is known, the Legal Entity Identifier or the European Unique Identifier must be givenBzst; a non-natural person without a domestic place of business must additionally give the tax identifier of the state of residenceBzst, and when that state assigned none, the legal form and date of incorporation are mandatoryBzst.

For investment funds under § 45b (2), first sentence, item 2(b) Einkommensteuergesetz, the Bundeszentralamt für Steuern tax number (BZSt-Steuernummer) may serve as an alternative identifier under margin note 13 of the Federal Ministry of Finance circular of 22 April 2025 on data transmission under §§ 45b and 45c EinkommensteuergesetzBzst, but the currently published XSD cannot carry a BZSt-SteuernummerBzst. When no other identifier under § 45b (2), first sentence, item 2(b) Einkommensteuergesetz is available, "5000000000013" must be entered in the Steuernummer data fieldBzst. The requirements for special investment funds with transparency option remain unaffected.

Attachments must not be sent with XML-based FM messagesBzst. Transmission through the DIP interface technically allows additional attachments alongside XML-based FM messages, but the MiKaDiv process does not support that function: the system does not capture, store or process attachmentsBzst, so omitting them keeps the data transfer smooth. The operative DIP setup is target procedure MIKADIVFM with specialist-procedure adapter V3.0Bzst and DIP interface 2.1Bzst.

Legal basis is §§ 45b and 45c Einkommensteuergesetz for the reporting duties, § 139c Abgabenordnung for the Wirtschafts-Identifikationsnummer, and the Federal Ministry of Finance circular of 22 April 2025 on data transmission under §§ 45b and 45c Einkommensteuergesetz for the investment-fund identifier alternative.