How do i apply an expense reciept to an invoice for profit/loss

Thanks for reaching out to the Community forum, mark804.

For me to be able to provide you with the best resolution, can you please provide additional information about the expense receipt you're referring to?

However, if you're trying to add billable expense to your invoice, here's what you'll need to do:

1. Click the Hamburger icon found at the top-left section.
2. Select the Plus icon and choose Invoice.
3. Pick the appropriate customer from the Customer ▼ drop-down menu,
4. From the Add to Invoice window at the right, select Add on the billable expense you want to charge to your customer.
5. Hit Save and close. 

To learn more about the detailed step by steps process I've provided above, visit this article: Enter billable expenses.

Looking forward to your response. Have a great weekend.

I'm not sure what you are asking

If you mean to make the expense billable, you have to have the plus version and turn on billable expenses in company settings and then 

then in company settings>advanced>chart of accounts click the edit pencil and select the billable expense income account

Why intuit separated the two related settings is anyone's guess

When you enter a vendor bill/CC charge/etc, you will see a Billable check mark box, check that and select the customer name in the customer block. The next time you invoice your customer, the system will show billable expenses on the right side that you can click the add link to add the bill to the invoice. IF you do not want to add the bill to the invoice, leave the billable check mark box blank, the cost of the expense will still count against the customer

Otherwise, the P&L shows all income reduced by all expenses.

You can run a P&L by customer, maybe that is what you want, but it will not be accurate unless you have billable expenses turned on and you selected the customer for the expense