A number of methodologies have been developed to review the probable integrity of subsea pipelines (flowlines, inter-field lines and main oil & gas export pipelines) in the absence of physical integrity data. Different methods may be applicable to different lines depending on the particular corrosion threat, the degree (or otherwise) in the confidence in the available process and/or the stability of the process itself and the type of chemical treatment program adopted. The methodologies developed and described in this paper have taken what is considered best practice from various industry standards relating to process pipework and modified them for use with pipelines.