Governments around the world are increasingly using technology to assist in making administrative decisions, and even to replace human decision-makers. In many cases this is entirely uncontroversial, allowing governments to make decisions faster and with greater consistency and accuracy. However, in some situations the use of technology has been controversial. It has resulted in unfair processes and outcomes and has reduced the ability of administrative law institutions to provide meaningful oversight of government decision-making. This paper will examine and compare how administrative law institutions and principles have applied and adapted to technology-assisted decision-making in Canada, Australia and the UK. In particular, it considers whether recent divergences in the development of the principles of fairness and reasonableness in the three jurisdictions has had an effect on the extent to which courts can meaningfully review the lawfulness of automated administrative decisions.