Firmaet samarbejder med verdens største pengeinstitutter, herunder [[Deutsche Bank]], [[HSBC]], [[Société Générale]], [[Credit Suisse]], UBS, [[Commerzbank]] og [[Nordea]].<ref name="gatekeeper" /><ref name="yle-nordea">{{Cite web|url=http://yle.fi/uutiset/mondays_papers_panama_papers_local_finns_party_vice_chair_sacked_world_champ_dreams_knocked_out/8785280|title=Monday's papers|date=4. april 2016|publisher=[[YLE]]|access-date=4. april 2016|archive-date= 6. april 2016|url-status=live|archive-url=https://web.archive.org/web/20160406024658/http://yle.fi/uutiset/mondays_papers_panama_papers_local_finns_party_vice_chair_sacked_world_champ_dreams_knocked_out/8785280}}</ref> Før Panama Papers-lækket blev Mossack Fonseca beskrevet af ''Economist'' som en "tight-lipped" (fåmælt) leder i branchen inden for offshore-økonomi.<ref>{{Cite web|url=http://www.vice.com/read/evil-llc-0000524-v21n12|title=The Law Firm That Works with Oligarchs, Money Launderers, and Dictators|last=Silverstein|first=Ken|date=3. december 2014|publisher=VICE Magazine|access-date=4. april 2016|website=Vice Media|archive-date= 4. april 2016|archive-url=https://web.archive.org/web/20160404025927/https://www.vice.com/read/evil-llc-0000524-v21n12|url-status=live}}</ref>
Journalistik Kriminalitet