Many assets in the UK sector of the North Sea are approaching or have passed the intended design life. The general decline for of many mature assets has been reversed as new operators invest significantly and target increased asset life when compared to the former owners. This poses a number of challenges for continued corrosion control. Some mature assets have seen multiple ownership transfers with repeat changes in corrosion management philosophies. For a mature asset historical records may be in various states of completeness. Operational conditions, likely to have changed radically since original design, may with investment be subject to increased requirements for gas lift, water injection and high water cuts. The new duty holder of a mature asset must take these factors into account when formulating their own corrosion management system. This publication examines the areas of concern to operators taking over ageing assets that are approaching or have exceeded design life. These include corrosion management, compatibility with increasing H2S levels (reservoir souring due to seawater breakthrough), corrosion mitigation, materials selection and fabric maintenance and repair. It discusses effective, but cost efficient methodologies that reflects the required future asset life.