Hi there, @mikey007.

You'll have to delete those transactions one at a time once they're already in the Credit Card register. This way, you can delete the American Express (AMEX) credit card account. Let me walk you through the steps.

1. Click the Gear icon.
2. Select Chart of Accounts.
3. Choose the AMEX credit card account, then click View register.
4. On the Register page, select each transaction, then click Delete.
5. Click Yes to confirm.

Once you're done deleting all the transactions, you can now inactivate the AMEX credit card account in the Chart of Accounts. Here's how:

1. Click the Gear icon.
2. Select Chart of Accounts.
3. Choose the AMEX credit card account.
4. Click the View register drop-down, then select Make inactive.
5. Hit Yes to confirm.

I've got you an article for more details: Remove Accounts.

However, if those transactions are currently on the Banking page, you can delete the entire transactions. Let me guide you how.

1. From the left menu, click Banking.
2. On the page, select the AMEX credit card account.
3. In the For Review tab, put a checkmark on each transaction.
4. Select Exclude Selected in the Batch actions drop-down.

Once done, all the transactions will be transferred to the Excluded tab. Then, you can now inactivate the account by following the steps above.

Here's how an article you can read on for your reference: Exclude Bank Transactions.

As always, feel free to visit our Help articles for QuickBooks Online in case you need tips and related articles in the future.

Just hit the Reply button if you have additional questions. I'll be right here to help.