Welcome to Community! Making changes to your QuickBooks Online subscription, can be done directly within your product. I would be glad to assist!
Before you make any changes to your subscription, I recommend following this link, to review our plans and their features. It's also important to note, if you're currently receiving a product discount, it's recommended to wait until the discount ends. By not doing so you will lose the current offer, as it will not transfer over. In addition, if you wish to downgrade your current plan, some of the features may need to be turned off. If you have multicurrency turned on, this cannot be deactivated.