UPDATE tblTransaction
SET Amount = SUM(R.Charge) + SUM(R.StateTax) + SUM(R.CityTax) + SUM(R.CountyTax) + SUM(R.ToStateTax) + SUM(R.FedTax) as BillableTotal
FROM tblCallRecord R
INNER JOIN tblInvoice I ON I.InvoiceID = R.InvoiceID
INNER JOIN tblTransaction T ON T.TransactionID = I.TransactionID
WHERE I.Batch=1912
GROUP BY R.ToNumber, R.InvoiceID
ORDER BY R.ToNumber