The recent sanctions imposed in response to the war in Ukraine have meant that the consequences of illegality under financial transactions such as derivatives, repo and securities lending have again been in the spotlight for financial institutions and their clients. The legal position varies across different market standard agreements. This article considers the relevant provisions in the ISDA aster Agreement (2002 version) (ISDA Master Agreement), the Global Master Securities Lending Agreement (2010 version) (GMSLA) and the Global Master Repurchase Agreement (2011 version) (GMRA), in each case assuming that the governing law is English law.