I have open a second account by mistake

Thanks for posting in the Community, @antonello-scamuz,

I can help you remove the second account you created in error. If you signed up for a trial, use the steps below to complete the cancellation:

1. Sign in to your QuickBooks Online account.
2. Click the Gear icon at the top right section of your Dashboard.
3. Tap Account and Settings.
4. Choose Billing & Subscription.
5. In the Payroll section, click Cancel or Cancel trial.
6. Hit Continue to cancel.
7. Answer the short survey, and select Confirm cancel.

However, if you we're billed for the subscription fee, I recommend contacting our Support Team first to discuss your billing and refund options. To get in touch with us:

1. Go to the (?) Help menu and choose Contact Us.
2. Enter Account Management and Billing in the box then press Let's talk.
3. Choose the Chat option to reach our live representatives.
   

For the steps to cancel an active subscription with us, use these steps below:

1. Go to the Settings ⚙ menu and then Account and Settings.
2. Click on the Billing and subscription tab.
3. Under QuickBooks section, pick Cancel subscription or Cancel online.
4. Hit Continue to cancel, then select Continue to cancel again (if applicable).
5. Follow the next steps.
6. Press Submit and cancel subscription then Got it.

I'm also adding some links about account cancellations to help you further:

• Cancel a QuickBooks Online subscription purchased through an app store
• Cancel your QuickBooks Online subscription

Feel free to ask again if you have other questions. I'll be right here if you need anything. Have a lovely day!