(5)Before Regulation (EU) No 648/2012 and Delegated Regulation (EU) 2016/2251 applied, counterparties to non-centrally cleared OTC derivative contracts were not required to exchange collateral, and bilateral trades were therefore not collateralised or they were collateralised on a voluntary basis. If counterparties were required to exchange collateral as a result of novating their contracts to address the withdrawal of the United Kingdom from the Union, the remaining counterparty may not be able to agree to the novation.