How can we add signature in voucher

Hi there, @userfinance1.

I want to make sure this is taken care of right away. Currently, adding a signature line to the voucher is unavailable. As a workaround, you can use the MEMO field to include the information you need. See the screenshot below: 

You may also check out a third-party application that integrates with QuickBooks and supports your desired functionality. You can directly visit the website for the QuickBooks Online’s App Center. 

For future reference, please browse through this article: Enter and pay bills. This link guides you on how to pay your bills through cheques or Pay bills and apply for partial credits. 

As always, you can get back to me if you have any additional questions. I'm here for you. Have a great day!