Thanks for reaching out here in the Community, paul103.
I'd be glad to provide some info regarding charges to your account.
Each QuickBooks Online account or company does require an additional subscription. If you have a second account, there will be a charge with the amount depending on which version of the product you're using. This information can be viewed by:
1. Clicking the Gear icon in the top right corner.
2. Select Account and Settings.
3. Choose the Billing & Subscription tab.
4. You'll see your subscription info under the Plan Details section.
The following article offers even more details about managing your plan: Update your billing and subscription info in QuickBooks Online.
I'll be here if you have any other questions. Just let me know by commenting below.