This paper provides an illustrative framework for blending hydrogen in an existing natural gas distribution network, based on a comprehensive study carried out in Ontario, Canada, between 2017 and 2019. The analytical and investigative work’s primary purpose was to determine a suitable concentration of hydrogen injection and a suitable location within a vast gas distribution system. The two-year-long study was based on literature reviews, analytical and integrity modelling, risk assessments, field surveys, in-house testing, industry consultation, and engineering judgement. Subsequent recommendations were validated against existing operational and design practices to identify and track potential gaps or incompatibilities to facilitate effective implementation.