How Retainage is Calculated on Invoices
Retainage is usually based on the entire invoice, but it may also be based on specific invoice sections.
For example, you may bill the reimbursable and consultant expenses in full when the invoice is issued, but apply a 10% retainage to the remaining invoice sections until you complete the project satisfactorily.
On the Misc tab of the Billing Terms form, you can enter a retainage percentage for each section of the invoice: labor, consultants, expenses, fees, units, or add-ons.