You can add an attachment to the expense in Moon Invoice easily by following the steps below.

1. Open the Moon Invoice application on your device or tap on this link.
2. From the main menu on your left, go to Purchases ➜ Expenses.
3. Click the ‘+’ icon to create an expense or select an existing one that you want.
4. Now, you can choose to ‘Upload from Computer’ or ‘Upload from Document’ for attachment.
5. Once selected, click on Save to apply the changes.