Hello there, @rob21_253.

Currently, it is not possible to collect signatures from customers for invoices. We can send a request to our product developers because we recognize how convenient it is for you and your company. We advise submitting feedback by doing the things listed below:

While the option is only accessible to customers with a Plus or Advance membership plan, I still advise getting in touch and submitting feedback to our product developers to let them know about this need. I'll demonstrate.

Here's how:

1. Go to the Gear icon.
2. Under Profile, select Feedback.
3. Describe how getting the signature for invoices is helping your business grow while using QuickBooks.
4. Select Next.
5. Click Skip and send message.

I've also added this post, which features a video on recording payments, for future reference: How to Record Customer Payments in the QuickBooks Mobile App.

Let me know if you have additional questions about managing invoices. I'm always here to help.