In August 1953, when the British colony and the two protectorates in the southern Africa, namely Southern Rhodesia, Northern Rhodesia and Nyasaland federated to become the Federation of Rhodesia and Nyasaland, Norman-Walker was temporarily seconded to the Federation's Cabinet Office to help facilitate its operation. In 1954, he returned to Nyasaland to serve as Development Secretary in the government. He was acting Financial Secretary for several occasions before being appointed Deputy Financial Secretary in 1960. A year later he was made an Officer of the Order of the British Empire and was appointed Secretary to the Treasury later in the year. When Nyasaland gained independence and renamed Malawi in 1964, Norman-Walker remained in the government and was made a Companion of the Order of St Michael and St George.