I'm here to share some information with you about how primary and additional credit cards sync transactions in QuickBooks, @emorales05.

Currently, we're unable to control what bank's give us the data. This is because the bank provides us with a static balance of the entire account, not the balance of each subaccount. That is why your primary account get the whole balance from both cards on the account.

So when your second card is associated with the primary card that pulling transactions into QBO, you can set this up as a sub-account. This way, you won't have to link this with online banking, only the primary account and the transactions will depend on how your bank delivers the data (your bank decides whether to sync it on the primary account or sub-accounts).

If you'll add a new card associated with the primary card, you can also set this up as a sub-account under the primary card. This will help fix and sync transactions with ease without using journal entries.

Here's how to change an existing account into a sub-account:

1. Go to Gear⚙ and then select Chart of Accounts.
2. Find the account and select the triangle ▼ in the Action column, then choose Edit.
3. Check the Is sub-account box and then select the parent account.
   
4. Select Save and Close.

Here's how to change an existing account into a sub-account:

1. Go to Gear⚙ and then select Chart of Accounts.
2. Find the account and select the triangle ▼ in the Action column, then choose Edit.
3. Check the Is sub-account box and then select the parent account.
4. Select Save and Close.

For more details about setting up a bank/credit card account with multiple cards associated with it, you can reference this article: About bank or credit card subaccount setup.

Additionally, you want to import old transactions from your bank, you can manually upload transactions into QBO.

Please keep me posted if you have other concerns with getting your online banking or credit card transactions into QuickBooks. I'm available to help anytime. Take care always.