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


Managing Partner, Attorney-at-law

with over 20 years of professional experience, focuses his practice on the corporate, company, commercial, business, and civil law, mergers and acquisitions (M&A), banking, finance, FinTech and financial regulation, Tech ventures, digital economy, Private Equity (PE) and Venture Capital (VC).

Jacek is considered as one of the Polish leading lawyers as regards advice for FinTech and financial innovation.


Tel: +48 695 137 353

Big Law Experience

Jacek is a seasoned professional (over 21 years of professional experience) qualified in Poland as both an attorney at law (radca prawny) and a tax adviser (doradca podatkowy). Jacek graduated from the Faculty of Law and Administration of the University of Warsaw (2000) and holds the Diploma of the Course of English and European Legal Studies from the University of Cambridge and the University of Warsaw (1998).

Jacek speaks Polish, English, and French.

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

Practice focus

In his practice, Jacek combines the profound knowledge and longstanding experience in corporate, commercial, and business law, mergers & acquisitions (M&A) transactions, financial and technology regulatory issues, and Private Equity (PE) and Venture Capital (VC) transactions.

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

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

Jacek is a leading practitioner and often advises and provides opinions on regulatory issues resulting from the newest trends in the finance and technology space, with a particular focus on financial innovation, FinTech, InsurTech, open banking, and payments regulations (based on EU payment services directives PSD and PSD2).

As an example of one of his most significant projects – Jacek advised T-Mobile Polska S.A. during drafting and 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

In the years 2017-2019, Jacek was a member of the Task Force for Financial Innovation (FinTech) affiliated at the Polish Financial Supervision Authority (Komisja Nadzoru Finansowego, KNF) which worked on removing barriers to the development of financial innovation and FinTech in Poland.

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

In 2016-2018 Jacek was a member of the Supervisory Board of the Association of Financial Companies in Poland (ZPF, the Polish Eurofinas member).

In 2013-2016 Jacek was 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 program committees member, moderator, and speaker at conferences and workshops. Jacek is also a co-originator of the annual FinTech Sector Congress organized by the Association of Financial Companies in Poland.

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

Representative Experience

  • Represented the international financer in the restructuring of debts of the Polish group of companies from the financial sector, including the preparing of security instruments documentation, and a successful collection (enforcement) of debts in the amount of over PLN 10 million.
  • Provided comprehensive advisory in the M&A transaction (preparing the share purchase agreement (SPA), negotiations, closing) – the divestment of the catering business in Poland, in favor of the international group with Scandinavian origins; the transaction was successfully managed and closed during the Covid-19 pandemic.
  • 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. (banking services offered by the telecom in cooperation with the bank under a “white label” scheme).
  • Advised during Incorporation of various types of commercial companies (e.g. limited liability companies (LLC), joint-stock companies) in Poland, and provided a full scope of legal advice to shareholders and companies in the process.
  • Prepared templates of Polish security instruments for an international lender.
  • Provided a legal opinion for an international investment firm on the regulatory framework of investment activity in Poland.
  • Represented an international lender in bankruptcy proceedings in Poland.
  • Represented an international lender in simplified restructuring proceedings in Poland.
  • Advised various consumer finance companies on consumer credit and online lending regulatory issues, including drafting of relevant documentation and day-to-day advice.
  • Advised the US- and UK -based owners of the Polish consumer lenders in the processes of finding investors and divestments of their Polish subsidiaries.
  • 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 lenders on the setting up of the intermediation structure compliant with Polish consumer credit regulations.
  • Advised UK-based leads collection company on the regulatory issues relating to lead generation in the life insurance space.
  • Represented clients (including consumer finance companies) in numerous proceedings before the Office for Competition and Consumer Protection (UOKiK) and the Financial Ombudsman.
  • Advised global Fintech and online lender on various legal and regulatory issues relating to online lending, anti-money laundering (AML), and other regulatory issues in Poland.
  • Advised a leading global provider of ATM solutions during the launch of the Polish operations including regulatory issues relating to the payment services regulations.
  • Advised 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 a global tires producer from Taiwan in its acquisition of the Danish tires producer as regards Polish aspects of the transaction.
  • Advised a leading global provider of electronic payment, transaction processing, and ATM solutions, during several planned acquisitions in Poland.
  • Advised a 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 a leading Polish Private Equity fund focused on technology during a planned acquisition of a board management software producer.
  • Advised the Polish companies of the global pharmaceutical group in relation to financing obtained by the group.
  • Advised a telecommunication operator from outside the EU on regulatory issues relating to payment services in Poland.
  • Advised one of Europe’s largest engineering consultancy firms on the sale of one of its subsidiaries in Poland to a group of managers.
  • Performed an audit of forms of security documents used by a leading Polish bank to ensure consistency and conformity with the latest legislation and jurisprudence.
  • Advised a Germany-based group of companies in the automotive sector on the refinancing of overdraft and investment credit facilities in Poland.
  • Advised 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.
  • Advised a multilateral European financing institution on the financing of the tram infrastructure assets for a municipally-owned transportation company.
  • Advised 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.
  • Advised an international renewable energy development and investment firm in the planned acquisition of a group of wind farms to be developed in central Poland.
  • Advised 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.
  • Advised a Private Equity fund on financing provided by a Polish bank for the acquisition of a waste management company in Poland (LBO transaction).
  • Advised 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.
  • Advised a UK-based investor on an acquisition of a private label production company in Poland.
  • Advised an international DIY retail group on a real estate sale and leaseback transaction.
  • Advised the Polish branch of a Germany-based press publisher on the acquisition of a newspaper in Poland.
  • Advised a Denmark-based client on the acquisition of a catering business in Poland.
  • Advised a worldwide supplier of fresh produce on a significant real estate leasing transaction related to a logistics center in Poland.


Partner, Attorney-at-law (adwokat) in the Warsaw Bar Association

is also a French law and European law lawyer, and has studied and graduated (after a 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 (adwokat) 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 has also graduated from the Executive Master in Management studies of HEC Paris and SGH Warsaw School of Economics.

Katarzyna TUSZYŃSKA-WIŚNIEWSKA manages our French desk and our francophone brand ADroit § and focuses her practice on business law, 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. Katarzyna in particular represented landlords and tenants in negotiations and execution of complex lease agreements in more than 130 commercial centers (malls) across Poland.

E-mail :

Tel: + 48 600 517 879