This was a case concerning the approach to assessing a person’s “ordinary residence” for the purposes of assessing which local authority is liable to pay for his/her care under s.21&24 of the National Assistance Act 1948. The Court adopted a purposive approach to the concept of “ordinary residence” in this context in order to avoid the prospect of a local authority avoiding responsibility for a person in need of care after their 18thbirthday by arranging a placement for them in another authority’s area prior to their 18th birthday. The case arose out of a dispute as to who should pay for the long term care needs of PH, a young man with severe physical and learning difficulties who is without speech and who lacks capacity to decide for himself where to live. Until the age of 4, PH had lived with his parents in Wiltshire. He then moved to live with foster parents in South Gloucestershire, where he lived until the age of 18. During that time he remained in contact with his parents, who moved to Cornwall. After reaching the age of 18, he lived in two care homes in the Somerset area. Pursuant to s.24 of the 1948 Act, the local authority liable to pay for PH’s care needs as an adult (the cost of which amounted to some £80,000 per year) was the authority in whose area he was “ordinarily resident” on his 18th birthday. The Secretary of State, who had been asked by the local authorities to exercise his power under secondary legislation to make a determination as to where PH was ordinarily resident for this purpose, determined that he had been ordinarily resident in Cornwall on his 18th birthday because, applying the language of Taylor J. in R v. Waltham Forest LBC ex parte Vale (unreported, 11 February 1985), himself applying the language of Lord Denning MR in In re P (GE) (An Infant) [196] Ch. 568, his ‘base’ was with his parents and they now lived in Cornwall. However, PH had not lived in Cornwall himself at any time of his life. The Secretary of State’s view was that this did not matter because, in the case of a person lacking in capacity to decide for himself where to live, it was necessary to look to the “seat of the decision-making power”, which in this case he concluded was with PH’s parents in Cornwall. Cornwall Council challenged the Secretary of State’s determination by way of a claim for judicial review. At first instance, Beatson J. (as he then was) dismissed the claim. On appeal, however, the Court of Appeal (Elias, Lewison and Floyd LJJ) quashed the Secretary of State’s determination, holding that there was no legal basis for concluding that PH had been ordinarily resident in Cornwall on his 18th birthday when he had never lived there. The Court of Appeal further concluded that the only rational conclusion on the material before the Secretary of State was that PH had on the relevant date been ordinarily resident in South Gloucestershire, where he had lived for over a decade and was undoubtedly the place he would have regarded as ‘home’. The Secretary of State appealed to the Supreme Court. Giving the lead judgment Lord Carnwath JSC (with whom Baroness Hale DPSC and Lords Hughes and Wilson JJSC agreed) held: The use of the word “base” by Lord Denning MR in In re P should be seen in context. There was nothing to suggest that he was intending to separate the idea of a “base” from the need for physical residence of some kind (para. 44). It was unhelpful to elide the test for ordinary residence set out in R v. Barnet LBC ex parte Shah [1983] A.C. 309 with the idea of a “base” (para. 47).