Hi vanessa-bevan-gm If you have a Plus account you'll be able to use the billable expenses feature.You can activate the feature by selecting the cog/gear icon > account and settings > expenses > Bills and expenses > make expenses billable. You will then have to create an expense and select the billable option and enter the customers name in the customer column. When you create an invoice for the customer you will see that the expense will appear on the right-hand side and you'll be able to add it to the invoice. If you don't have a Plus account you'll have to create an expense account for mileage in the chart of accounts then create a product and service for mileage and select the mileage expense account you set up in the chart of accounts, in the income account field.
