You can change the address in both the mobile app and online desktop version of your InvestEngine account, by going into Settings.
In the online account, you can find it by clicking on "More" > "Settings" in the top right-hand side of the screen. Your contact details will appear on the new page, where you will be able to amend your address.
Most addresses get verified automatically, however sometimes you will be prompted to upload a proof of address. We accept driving licence, bank statement, utility bill (water, gas or electric only), as long as they are dated within the past 3 months.