None of my Sychrony accounts will connect.

I appreciate the efforts you've made trying to connect your Synchrony accounts to QuickBooks Online, @kpad3300. Allow me to further discuss what Error 324 means and walk you through some troubleshooting steps for a successful bank connection.

Error 324 in QuickBooks occurs when the program can't access the bank or credit card account you want to sync, possibly due to incorrect credentials, changes to the bank’s website, or problems with the bank itself.

Here are some possible reasons for this error:

• Your bank or credit card company has modified the account or shifted it to a different server.
• You've updated the account name or other details on your bank or credit card company's website.
• Your bank or credit card company has issued you a new account or credit card.
• You've closed your bank or credit card account.
• You have multiple accounts with the same name at the bank.

Then, here's how you can rename an account if in case multiple accounts have the same name:

1. Navigate to Transactions, then select Bank transactions (Take me there).
2. Choose the bank account that you wish to rename and click on the pencil icon .
3. Select Edit account info.
4. In the Name field, update account name.
5. Finally, click Save and Close.

After which, you can also proceed and update your connection. For the detailed steps how and to know what other things to perform depending on your unique situation, check out this article: Fix banking error 324 in QuickBooks Online and QuickBooks Self-Employed.

Alternatively, you can also consider uploading transactions if resolving the issue might take a while.

For your future reference, you can open this article for automatic categorization: Set up bank rules to categorize online banking transactions in QuickBooks Online.

Linking your bank account is a top priority as it can improve your business operations. I'm always available to offer assistance if you have further questions about this process.