As the energy transition continues, the importance of long-distance energy transportation remains crucial for global supply chains. The article discusses the hydrocarbon industry's exploration of repurposing pipelines for hydrogen as part of diversification strategies. While this move presents opportunities for the hydrogen industry to tap into existing infrastructure, financial barriers and technical modifications hinder broader development. To convert pipelines from oil and gas transportation to hydrogen, various modifications to materials and systems are necessary. Challenges include the risk of hydrogen embrittlement in pipeline steels and the need for materials like austenitic stainless steel and fibre-reinforced polymer for enhanced corrosion resistance and reduced installation costs. Hydrogen's lower energy density compared to natural gas requires adjustments in pipeline diameter and compressor capabilities. Safety measures must be enhanced due to hydrogen's high flammability and low ignition energy, necessitating changes in hazardous zones and venting strategies. Despite these challenges, the repurposing of pipelines for hydrogen is an area of active innovation and research. Emerging solutions like pipe-in-pipe systems offer a way to address safety concerns by capturing leaked hydrogen within the interstitial space. This transformation also involves industry consensus on maintenance practices and operational changes to ensure the safe and efficient transport of hydrogen.