How do I find out what a deposit has been partially matched against? It will not allow me to exclude it.

I can help you locate the partially matched deposit and ensure you can exclude it from your QuickBooks Online (QBO). Let’s go through the process together.

In QBO, you can't exclude partially matched transactions. To resolve this issue, I recommend unmatching the transaction from the entry in QBO. Here's how:

1. Go to Transactions and select Bank Transactions.
2. Choose the tile for the account you want to review.
3. Select the Categorized tab.
4. Find the transaction you wish to unmatch.
5. Click on the blue transaction link in the Added or Matched column to view the partially matched transaction.
6. Select the Undo option under the Action column. This will move it back to For Review.
7. From the For review tab, find and check the box for the partially matched deposit.
8. Select the Exclude option. 

For the complete guide on excluding bank transactions, please see this article: Exclude a bank transaction you downloaded into QuickBooks Online.

If the issue persists, you can consider creating a journal entry transaction to remove the partially matched deposits. It's advisable to consult with your accountant to ensure that balances remain unaffected and your financial data stays accurate.

Additionally, make it a practice to reconcile your accounts in QBO regularly. If you need assistance with reconciling or fixing any discrepancies in the future, check out this resource: Learn the reconcile workflow in QuickBooks.

Please keep me updated on how things go in the comments below. If you have any further questions or concerns about identifying and excluding partially matched deposits, I’m always here to help.