Hello there, @1angryscotsman. Thanks for getting back to us.

It would be best to contact our support team to check if you'll be getting a charge or not when switching back to your previous plan. Once our specialist validates it, you can go through with the process. Let's follow the steps below to contact them:

1. Go to Help at the upper-right corner.
2. Enter a short description of your concern. 
3. Click Talk to a human. Then, I still need a human.
4. You can then get a callback or send a message to start a conversation with our specialist.

You may want to check the articles below for additional information about managing subscription in QuickBooks:

• Subscription management. 
• Update the payment method or info for your QuickBooks Online subscription.

Let me know if you have other questions. I'm right here to help. Stay safe.