Currently, there isn't an option to customize the bill payment check, serek.

You can only customize the fields and appearance of the invoice. I'm adding this link as your reference: Customize form templates in QuickBooks Desktop for MAC.

If you also need to customize your reports, check out this article for instructions: Customize reports in QuickBooks Desktop for Mac.

Don't hesitate to post again if you have other customization concerns. I'll be around to help you.