- Overview
- Braunschweig
- Marten Siebke
Lawyer and notary profile
Marten Siebke
Civil-law notary (Notar) · Certified specialist in insolvency and restructuring law (Fachanwalt für Insolvenz- und Sanierungsrecht), Kosswig Rechtsanwälte, Braunschweig
- Checked in the official register of the German Federal Bar (BRAK) on 21 October 2026
- Overall rating 4.3 of 5
, from 46 reviews of the firm
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- Languages
- English, Spanish
- Focus areas
- Employment law (Arbeitsrecht), Marriage and family law (Ehe- und Familienrecht), Insolvency law (Insolvenzrecht), Brokers' and estate agents' law (Maklerrecht), White-collar criminal law (Wirtschaftsstrafrecht), Bau- und Immobilienrecht, Inheritance law (Erbrecht), Family law (Familienrecht), Traffic law (Verkehrsrecht), Hunting law (Jagdrecht), Medical law (Medizinrecht), Construction law (Baurecht)
- Opening hours
- Monday to Thursday: 8:00 to 13:00 and 14:00 to 17:00
- Friday: 8:00 to 13:00
Sources: the firm's website, retrieved on 24 October 2026; Deutsche Anwaltauskunft des Deutschen Anwaltvereins, retrieved on 12 October 2026. Focus areas and opening hours are the lawyer's or firm's own words. Focus areas from the directories' fixed lists have an English label with the German term in brackets; all others stay in German.
Location of the firm
Reviews of the firm
4.3 of 5 Overall rating from 46 reviews on 2 platforms. How we calculate the overall rating
| Platform | Rating | Reviews | As of |
|---|---|---|---|
| Das Örtliche | 5.0 of 5 | 1 | 21 October 2026 |
| 4.3 of 5 | 45 | 22 October 2026 |
These reviews apply to the firm, not to individual lawyers.
Details from the official lawyer register
- Name
- Marten Siebke
- Professional title
- Lawyer and civil-law notary (Rechtsanwalt Notar)
- Specialist titles
- Certified specialist in insolvency and restructuring law (Fachanwalt für Insolvenz- und Sanierungsrecht)
- Regional bar association
- Braunschweig
- Admitted since
- 31 March 2010
- First admission
- 24 March 2010
- Law firm
- Kosswig Rechtsanwälte
- Firm address
- Zuckerbergweg 1, 38124 Braunschweig
- siebke@kosswig.com
- Website
- www.kosswig.com
- Identifier in the special electronic lawyer mailbox (beA)
- DE.BRAK.9a5fa004-258b-4d32-8965-7c9e6417ddfd.6b30
Source: Official lawyer register of the German Federal Bar under section 31 of the Federal Lawyers' Act (BRAO). The register is kept in German. We show names and addresses as the register gives them and add an English description to German professional titles.
Details from the register of notaries (Notarverzeichnis) of the Federal Chamber of Notaries (Bundesnotarkammer)
- Name
- Marten Siebke
- Official title
- Lawyer and civil-law notary (Rechtsanwalt und Notar)
- Official seat (Amtssitz)
- Braunschweig
- Chamber of notaries
- Notarkammer Braunschweig
- Appointed since
- 24 March 2021
- Partnership
- Kosswig Rechtsanwälte
- Office
- Zuckerbergweg 1, 38124 Braunschweig
- Phone
- 0531 264 04 0
- Fax
- 0531 264 04 99
- siebke@kosswig.com
- Website
- www.kosswig.com
Source: Notarverzeichnis der Bundesnotarkammer (§ 78l BNotO), as of 28 October 2026. The register is kept in German.
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