Thanks for joining us here in the Community, @tisaocean.

I got your back in managing the sales prepayment that you've entered in QuickBooks Online.

You'll need to check the set up of the other payment that was not showing up. This way, you can make necessary corrections so it would be posted correctly.

If you can't find the transaction, you can search it from the Audit Log. From there, you can modify the transaction.

To do that:

1. Go to Gear icon.
2. Click on Audit Log.
3. Select Filter.
4. Use the fields on the Filter panel to choose the appropriate User, Date, or Events filter to narrow the results.
5. Select Apply.

Once done, you can create a sales tax adjustment to decrease your sales tax amount due. 

To do that:

1. Click the Taxes menu from the left menu.
2. Select the agency you're recording the payment.
3. Click Record Tax Payment.
4. Fill all the necessary information.
5. Mark the Make Adjustment box, then enter information about the adjustment.
6. Select Record Tax Payment.

Here's a great resource that you can check on for more detailed steps: Manage Sales Tax Payment.

If you're using the Automated Sales Tax feature, here's how to make Sales tax adjustment:

1. Click the Taxes menu from the left menu.
2. Select the agency you're paying.
3. Click View return.
4. Click the + Add an adjustment link.
5. Enter the reason for the adjustment, the account and the amount.
6. Once done, select Record payment.

You can check out this article for more detailed steps: Set up and use Automated Sales Tax.

You're always welcome to visit the Community again if you have any other questions with taxes. I'd be more than happy to help. Have a good one!