When you classify an expense claim you will be provided with a billable option if the task or project you are claiming expenses for is billable. Wait for the checkbox to load (it takes 1-2 seconds) and then uncheck the billable box if this claim is non-billable to the client. You can still get reimbursed for it (see next step below).

Expenses booking to a department, an internal project or non-billable task cannot be marked as client billable.

When you enter an expense claim item it will automatically be marked as reimbursable (as shown in item list in purple, item details in orange) unless you imported the transaction from a bank card which was set-up originally as a company paid bank card. If the expense was company paid (or paid for by a colleague who is making their own claim) then be sure to mark the item as non-reimbursable by clicking on the reimbursable column until it becomes a negative/no-entry sign.

You can enter billable/reimbursable, non-billable/reimbursable and billable/non-reimbursable claims. There is no reason to enter non-billable/non-reimbursable claims unless it is purely to record project costs.