I would like to remove the field 'customer' in the supplier bill input page. How can I do that?

I can help you with removing the Customer field from your Bill page, @lubru.

The Customer field or column is use to track expenses and purchases by customers. However, you can easily remove this column from your Account and Settings if you'll not be using it. 

Follow the steps below:

1. Go to the Gear icon and select Account and Settings.
2. Proceed to the Expenses section and then turn Off the option for Track expenses and items by customer and Make expenses and items billable. 
3. Click on the Save button and then Done to save the changes. 

For more information about billable expense tracking and adding it to a customer invoice, check out this article: Enter billable expenses.

Once you've paid the bill, here's how to record cash, cheque, and credit card payments: Enter bills and record bill payments in QuickBooks Online.

Let me know if you need further help removing the Customer column by leaving a reply below. Keep safe, and have a great rest of the day!