Expense not in Price List

Expense not in Price List

Hi,

Great that I can add unbilled expenses when I invoice my customer. However, for a customer using a custom price list, Zoho Invoice tells me that " Automobile Expense  is not in the price list  PriceListUSA . Please  enter the item rate manually .. This does not make sense when I have a specific expense such as "Gas $33" with a specific amount already attached to it. What do I do?

Many thanks