If you’ve logged the purchase invoices for the travel expenses and subsistence you can rebill these to a client sales invoice. Doing it this way will ensure that the original expense code is contra’d.
Simply locate the purchase expense invoice on the main list, check the item, click on the “More options” menu and click “Rebill to client”.
This will open a new sales invoice with a reverse entry on the expense code. You can edit the invoice to add more items if you wish.
You can find more on expense rebilling here.
Hope that helps!