The establishment of the International Phonetic Association and the creation of its alphabet (the IPA) attest to the fact that scientific advancement emerges from collective collaboration and sustained debate. The development of the IPA is closely intertwined with progress in the fields of phonology and phonetics. However, the founders of the Association — such as Paul Passy, Otto Jespersen, and Wilhelm Viëtor —alongside influential scholars like Isaac Pitman, Alexander Ellis, and Henry Sweet, were also ardent advocates of spelling reform. We examine the extent to which this reformist agenda influenced the evolution of the IPA, with particular focus on debates within the Maître Phonétique concerning the concepts of ‘phonetic transcription’ and ‘phonetic spelling.’ We show that spelling reform was consistently viewed as a core concern and constituted a persistent, underlying thread in the evolution of the IPA. We argue that much of the debate between Sweet, Passy and Jones in Le Maître Phonétique had no winner as such. However, the adoption of Sweet’s ‘broad’ transcriptions preferentially based on Latin-based symbols identically used across languages led to a confusion between the task of phonology/phonetics, the devising of spelling systems and the pedagogical applications of the IPA.