The focus of our firm, areas of expertise and experience stems from the extensive experience and areas of interest of our partners Jacek WIŚNIEWSKI and Katarzyna TUSZYŃSKA-WIŚNIEWSKA.



Attorney-at-law, Managing Partner, focuses his practice on corporate, commercial and business law, finance, FinTech and financial regulation, Tech ventures, digital economy, mergers and acquisitions (M&A), private equity (PE) and venture capital (VC).


Tel: +48 695 137 353

Big Law Experience

Jacek is a seasoned professional (20 years of experience) qualified in Poland as both an attorney at law (radca prawny) and a tax adviser (doradca podatkowy), and holds the Diploma of the Course of English and European Legal Studies from the University of Cambridge. Jacek speaks Polish, English, and French.

Before founding #WIŚ Jacek was practicing for over 18 years at renowned international law firms with French (Mazars, 2000-2006), German (Noerr, 2007-2011), and US origins (Squire Patton Boggs, 2011-2018).

Practice focus

In his practice, Jacek combines the profound knowledge and longstanding experience in commercial and business law, financial and technology regulatory issues and various types of corporate M&A, JV, and PE/VC transactions, while he also closely follows and advises on the most current trends in finance and Tech space, with particular interest in financial innovation, FinTech, InsurTech, open banking, and PSD2 related issues.

In his financial services practice, Jacek advises on transactional and regulatory issues in banking, finance, FinTech and InsurTech space, including acquisition financing, consumer finance (also consumer credit issues for non-banking cash loan firms), cross-border securitization and other receivables related transactions, and leasing and sale and leaseback transactions. Jacek advises PE/VC funds on leveraged buy-out (LBO) transactions and various parties on the LMA type financing transactions.

Within corporate M&A space Jacek has considerable experience in advising multinational and Poland-based clients during buyouts, divestments, and transformations of commercial companies in many sectors (with a particular focus on financial services), and in setting up of complex joint venture structures.

Jacek is often providing opinions on regulatory issues relating to new business models relating to FinTech, financial services, banking, and insurance services to foreign and Polish Tech investors and innovative Tech companies.

As an example of one of his significant projects, Jacek advised T-Mobile Polska S.A. during negotiations of the strategic co-operation agreement on the provision of financial intermediation services with Alior Bank S.A. which resulted in a globally pioneering project of co-operation between the telecom and the bank to provide financial services in the “white label” scheme under “T-Mobile Usługi Bankowe dostarczane przez Alior Bank” name. A similar co-operation scheme was later used in the provision of financial services of various telecoms and financial institutions in Poland and abroad.

Functions and Memberships

Since 2017 Jacek is a member of the Task Force for Financial Innovation (FinTech) affiliated at the Polish Financial Supervision Authority (Komisja Nadzoru Finansowego) which works on removing barriers to the development of financial innovation and FinTech in Poland.

Since 2016 Jacek is an Awards Committee Member of Loan Magazine Awards granted to the best Polish non-bank lenders, their managers, and supporting companies.

In 2016-2018 Jacek was also a member of the Supervisory Board of the Conference of Financial Companies in Poland (the Polish Eurofinas member) and is generally a legal industry leader and well-known figure in the finance, FinTech and Tech space in Poland.

In 2013-2016 Jacek was also a member (judge) of the Discipline Court of the Warsaw Bar Association (the largest legal profession association in Poland).

Events’ Moderator and SPIRITUS MOVENS

Jacek is a very frequent programme committees member, moderator and speaker at conferences and workshops and co-originator of the annual FinTech Sector Congress organized by the Conference of Financial Companies in Poland.

Since 2016 Jacek is also an originator and chair of monthly events for FinTech and banking professionals, investors and enthusiasts, currently under #TechVoice brand. If you are interested in attending these events please reach out to Jacek.

Jacek was also an originator and regional and Polish leader of O-I-CEE! Legal News and Views blog where CEE attorneys publish their insight on CEE-region related legal issues.

Representative Experience

  • Advising T-Mobile Polska S.A. during negotiations of the strategic co-operation agreement on the provision of financial intermediation services with Alior Bank S.A.
  • Advised various consumer finance companies on consumer credit and online lending regulatory issues, including drafting of relevant documentation and day-to-day advice.
  • Advised US and UK -based owners of the Polish consumer lenders in the processes of finding investors and divestment of their Polish subsidiaries. services regulatory issues.
  • Advised global crowdlending marketplace firm on banking and payment services regulatory issues.
  • Provided a group of InsurTech and Insurance firms with a legal opinion on regulatory aspects of their Polish operations under the consumer credit regulations.
  • Advised Polish consumer lender on the setting up of the intermediation structure compliant with consumer credit regulations.
  • Advised UK-based leads collection company on the regulatory issues relating to the lead generation in the life insurance space.
  • Represented consumer finance companies in numerous proceedings before the Office for Competition and Consumer Protection (UOKiK) and the Financial Ombudsman.
  • Advising a leading global provider of ATM solutions during the launch of the Polish operations including regulatory issues relating to the payment services regulations.
  • Advising a US-based consumer finance company on the launch of its consumer finance operations (cash loans business) in Poland, including drafting of relevant documentation, regulatory (consumer credit) issues, followed by day-to-day advice for the Polish subsidiary.
  • Advised global tires producer from Taiwan in its acquisition of the Danish tires producer as regards Polish aspects of the transaction.
  • Advising the leading global provider of electronic payment, transaction processing, and ATM solutions, during several planned acquisitions in Poland.
  • Advised the leading Polish venture capital fund in the financing of its acquisition of a cosmetics producer.
  • Advised various European factoring providers on the Polish law aspects of cross-border factoring transactions.
  • Advised the Polish subsidiary of the US-based consumer lender on all legal aspects of the launching of the online lending business in Poland.
  • Advised a leading European financial institution during various cross-border factoring and securitization transactions.
  • Advised leading Polish Private Equity fund focused on technology during a planned acquisition of board management software producer.
  • Advising the Polish companies of the global pharmaceutical group in relation to financing obtained by the group.
  • Advising a telecommunication operator from outside the EU on regulatory issues relating to payment services in Poland.
  • Advising one of Europe’s largest engineering consultancy firms on the sale of one of its subsidiaries in Poland to a group of managers.
  • Performing an audit of forms of security documents used by a leading Polish bank to ensure consistency and conformity with the latest legislation and jurisprudence.
  • Advising a Germany-based group of companies in the automotive sector on the refinancing of overdraft and investment credit facilities in Poland.
  • Advising an independent, Germany-based and internationally operating service provider for the servicing of complex financial portfolios (acting as security agent) during the restructuring of financing provided to a Germany-based group of companies by the bank syndicate.
  • Advising a multilateral financing institution on the financing of tram infrastructure assets for a municipally-owned transportation company.
  • Advising Autostrada Wielkopolska II S.A. (AWSA II), the project company for Poland’s A2 toll motorway Section II during negotiations with the General Director for National Roads and Motorways (GDDKiA) on the annex to the construction and operation agreement.
  • Advising an international renewable energy development and investment firm in the planned acquisition of a group of wind farms to be developed in central Poland.
  • Advising an international renewable energy development and investment firm in the sale (assignment) of project rights to a part of a wind farm to be developed in central Poland.
  • Advising a private equity fund on financing provided by a Polish bank for the acquisition of a waste management company in Poland (LBO transaction).
  • Advising an international renewable power producer on the planned acquisition of shares in a special purpose vehicle (SPV) created for the purposes of the development of a wind farm in central Poland.
  • Advising a UK-based investor on an acquisition of a private label production company in Poland.
  • Advising an international DIY retail group on a real estate sale and leaseback transaction.
  • Advising the Polish branch of a Germany-based publisher on the acquisition of a newspaper in Poland.
  • Advising a Denmark-based client on the acquisition of a catering business in Poland.
  • Advising a worldwide supplier of fresh produce on a significant real estate leasing transaction related to a logistics center in Poland.



Attorney-at-law, Partner. Attorney-at-law (adwokat) in the Warsaw Bar Association, is a French law and European law lawyer, and has studied and graduated (after full legal course) from the Robert Schuman University in Strasbourg (l’Université Robert Schuman de Strasbourg, DEUG en droit, Licence en droit européen et international, Maîtrise en droit général, Certificat en droit de l’Union Européenne, DEA en droit des Communautés Européennes), and from the Institute of Legal Studies in Toulouse (l’Institut d’Etudes Judiciaires de Toulouse). Katarzyna is also a Polish lawyer and attorney-at-law after the nostrification of her French diploma at the Faculty of Law and Administration of the University of Warsaw, and after the advocate training (aplikacja adwokacka) at the Warsaw Bar Association.

Katarzyna TUSZYŃSKA-WIŚNIEWSKA manages our francophone brand ADroit § and focuses her practice on business law (she has additionally graduated from the Executive Master in Management studies of HEC Paris and SGH Warsaw School of Economics), corporate law, commercial law, real estate law (including advice during acquisitions of real estate located in France and in Poland, and advice in drafting and negotiating complex lease agreements, in particular relating to commercial centers in Poland), European law, civil law, and family law. Katarzyna has over 15 years of experience in legal and transactional advice on the Polish-French market.

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Tel: + 48 600 517 879