How do PayPal incomplete payments work?

How does the pending payment process work with PayPal? Will the payment fall off or will it be eventually processed?

An Incomplete Payment would mean that:

1. A user submitted your form

2. He's redirected to Paypal for the payment

3. He never completes the payment

So it is basically something that can't be charged at all, even if you manually complete it. The only thing that will happen once you manually complete an Incomplete Payment is it will be treated as a regular submission, so your email alerts would fire off and so it would be recorded on your Submissions Page.

Here's a snippet from the guide I'm linking below:

Note: Completing a submissions will NOT process any payment as there was no payment information to begin with. The system will simply treat this as a regular submission so it can be included on form reports, and that email alerts can be fired off as usual.

Related guides:

How-to-view-incomplete-payments

Paypal-Incomplete-Payments-FAQ