You can change your bexio package whenever you like. Please see the GIF below.
What happens when you upgrade (increase the package or order an add-on)?
If you upgrade the package, buy another licence or order a paid add-on, the adjustment will take effect immediately and you will receive a proportional invoice a few working days later with the additional costs for the remainder of the current billing period.
What happens in the event of a downgrade (reduction of the package or cancellation of an add-on)?
If you downgrade a package, delete a licence or cancel a chargeable add-on, the adjustment will also take effect immediately. The amount overpaid as a result will be credited to you and offset against the next invoice.