Mobile app does not allow adding customer to billable receipts

Good observation, Userhudthudson. You're unable to add billable expenses to a customer in the mobile app.

You'll want to add the billable expense through the web. Here's how:

1. Click the New or Plus sign (+) button.
2. Go to Invoice.
3. Select the customer.
4. Under Add to Invoice, select the Billable expense, then click Add.
5. Click Save and close. 

For more information, you can refer to this article: Enter billable expenses.

Feel free to let us know if you need more help. We're just around to assist you. Take care!