As an Admin, you can choose whether certain fields are required or optional for users to fill in when they are creating expenses. 

You can configure the following fields as required or optional to fill in:

• Merchant
• Category
• Project
• Paid with (payment method)
• Comment
• Country
• Tax rate 

1. Go to Admin settings.

2. Go to Advanced settings page.

3. Check or uncheck the relevant settings and don't forget to save.