The potential internal corrosion threats from handling and processing produced fluids and gases are generally more complex in nature and more aggressive to address than external corrosion. In contrast, the continuing development of coatings technology used singly and, where subsea and buried infrastructure is concerned, in tandem with the robust and well-established technology and practice of cathodic protection (CP), means external corrosion can arguably be engineered and managed more confidently than for internal corrosion. The implications of internal corrosion threats should be considered both at the design stage and to effectively and consistently manage during operating life, and should be considered far more likely to determine materials selection. However, it is the quality of application or poor provision of appropriate through-life corrosion management programme and implementation of effective corrosion mitigating measures and continual supporting maintenance that are more likely the primary causes of premature failure by internal corrosion threat.