How can I rectify a problem where some of my customer invoices are showing a zero balance, but not as "Paid". So they remain in our Trust Liabilities account.

hi @b00kkeeper45 

You need to link the payment to the invoice.  At the moment, QB has a payment & an invoice for the amount - so balance is £nil - but the two aren't linked, so they will both show as open.

Go to Receive Payment for the customer.  Select both the invoice & the credit - this will create a £nil payment but will link the two & show both as cleared.

Hope this helps.