You're already on the right track in setting up your credit card account and managing transactions in QuickBooks Online (QBO), @bdeshazer. I'm here to share further insights about this.

When you connect to online banking, you'll first need to know how your bank sends the downloaded transactions. If the transactions download to one account, connect only the parent account. If the transactions download to the individual accounts, connect the subaccounts and not the parent account.

You can’t connect both a parent account and its subaccounts. Since all the charges will sync with your parent account, you're unable to make them automatically go to a subaccount. You may exclude those transactions and manually add or assign each of them to the appropriate card numbered subaccount. This way, you can avoid duplicates and keep your data updated and accurate.

To exclude, here's how:

1. Go to the Banking menu .
2. Select the Banking tab.
3. Choose  the tile for the account you want to review.
4. Go to the For Review tab.
5. Select the checkbox of the transactions to exclude.
6. Click Exclude. 

Also, when it’s time to reconcile (every month), you only need to reconcile the parent account. This is because all transactions in the subaccounts roll up into it. For the step-by-step guide, I'd recommend checking out this article: Reconcile an account in QuickBooks Online.

Keep me posted in the comments if you have other banking concerns and questions about managing credit card transactions in QBO. I'm always around to help. Take care, and I wish you continued success, @bdeshazer.