Gear rental, a generator, airfare reimbursement, per diems — anything you need to bill on top of the guarantee goes in as a billable expense on the booking. Don't free-type an extra line onto an invoice: expenses entered properly flow through to settlement and analytics, and free-typed ones don't.
Add the extra as a billable expense
Open the booking and go to the Terms tab.
Open Artist Expenses.
Add a row for each extra and mark it as a Billable expense. Name it plainly — "Generator Rental", "Airfare Reimbursement" — so it reads well on the invoice and in reports.
Enter the amount.
Attach the receipt to the expense row while you're there. Receipts live with the expense, so your buyer and your own records both stay tidy.
Save the booking.
Then decide how to bill it
You have two options, and it's worth choosing before you create anything:
Roll it into the balance. Go to the Payments tab, open Invoices, and build one itemized invoice carrying the balance plus each billable expense as its own line. Your buyer pays once.
Invoice it separately. Create a separate expense invoice on the same booking, leaving the balance invoice as it is.
Either way, create the invoice the normal way: Preview Draft, then Create Invoice in the Document Preview panel.
Good to know
Add every expense before you create the invoice. Expenses lock once an invoice is recorded, and unlocking them isn't something you can do yourself.
Expenses from different bookings can't be combined onto one invoice. If a buyer owes you across several bookings, they'll receive several invoices.
A deduction works the same way in reverse — see the article on invoicing only your share when a sub-agency takes commission.