Updating financial details in your OnePlan account
From your OnePlan dashboard, click the arrow next to your avatar in the top right-hand corner. Click 'Payment details'
This will bring up a pop-up allowing you to input the Name on your card, Card Number, Expiry Date and CVV. Click 'add' - at this stage, you might be re-directed to your bank page for 3D secure verification.
These card details will be stored against your account and your card will automatically be charged as your paid subscription with OnePlan renews (if you have one).