To increase a customer's price, you will need to edit their subscription.

The new price may already be an option in Stora, but if not, you can create a unique price against the unit type (50 sq ft, etc.). More information on how to do this can be found here.

When you have created your new price point, navigate to your customer's subscription. Select the Edit Unit Types option, as shown below.

You can then select the new price, and you will be able to select when to start the change immediately on the next renewal or backdate. (The recommended option is 'on next renewal' as you will likely have given the customer notice of the increase)

Select 'Preview Changes' to review and then 'Change units' to confirm the change.