In this Current Controversy article, I describe and analyse the imminent move to a system of deemed consent for deceased organ donation in England and similar planned changes in Scotland, in light of evidence from Wales, where the system changed in 2015. Although the media has tended to focus on the potential benefits and ethical issues relating to the main change from an opt-in default to an opt-out one, other defaults will also change, while some will remain the same. Interaction (...) of these other defaults with the principal one raise several ethical issues that may complicate efforts to use deemed consent to increase donation rates. Most significantly, changing the main default will have the effect of changing the default for patients' families, who play a vital role in the consent process. (shrink)