A late fee automatically added by Syncro to invoices is treated as a non-inventory item and thus syncs over to QB using the Default QuickBooks Product defined in your QuickBooks settings (Admin > Apps > Quickbooks > Sync Settings).
If you want a specific late fee item to sync to QB, you will need to create your own Late Fee item in your Products & Services and then manually add it to any late invoices.
If the late fee is non-taxable, then make sure the Default QB Tax code for non-tax items is set to a non-taxable QB code (found on the same settings page).
You will also need to make sure none of your Payment Terms include a late fee so that you can manually add your own.
The problem with this is there is no 2-way sync. Wen the late fee is added to Quickbooks invoice (or quickbooks is used to add a late fee), the invoices do not match. Then, when payment is taken, there is a credit balance in Syncro because the payment is more than the invoice.
How do we correct that discrepancy?
Since there’s no 2-way sync you’ll have to make an item in Syncro for late fees and that will sync, or you’ll need to update the fees in QB manually.
I understood that, and is what I said. But, how do we correct the discrepancy between the payment amount and the invoice amount in Syncro (which is different from quickbooks). I am pointing out that your instructions here create a sync problem, and the payment will leave a false credit in Syncro. I know this for fact, because I am dealing with this very issue right now.
I’d like to take a look at that, I’ve started a ticket for you which should be in your inbox shortly!