Hold back is an amount on a work order held back from invoices to be invoiced at the end.
There are two fields on the Add Work Order Type form (Setup > Operations > Work Order Types) related to hold back:
Hold Back %: This defaults to zero; 1 equals 100%.
Hold Back Item: This is hidden until the Hold Back % is greater than zero.
If generating a progress invoice or an invoice before completing a work order that is using a work order type with a hold back percentage, the hold back item is added automatically. After completing the work order, generate an invoice to collect the hold back amounts that were withheld from the invoices generated before completing the work order.
For example: There is a work order type using a Hold Back percentage of 10%. Generate an invoice for the work order with total charges of $10,500 (before tax). A hold back item is added automatically with a total of $1,050 (which is 10% of the $10,500 before tax work order total) as a negative value to the invoice. When the work order is marked as complete, generate an invoice to collect all the hold back amounts that were withheld from previous invoices. To do this, add the same hold back item that was used on previous invoices to a new invoice for the sum of all prior amounts attached to invoices, but this time as a positive amount. In this example, add the hold back item to a new invoice for a total of $1,050.