Here's how Plannit keeps track of payment information and how to access it quickly on a given invoice:

When you open the paid invoice, simply go to section 3 (Payment Schedule) and consult the "Method" column (see below).

To access the information in mobile mode, simply click on the payment line and the information will appear in the window as follows:

This information is available for each payment line on any given invoice to find it easily when needed.