A small thing I like to share with you.
I only use POS for sales, however people 1) pay next time, pay by bank, pay cash, or pay by card (most of them thanks god).
Using the POS the options for "debtor management" is limited.
I found quite an efficient system to see who paid and who not. I do not submit if the invoice is not settled. On the list menu just clicking "drafts" shows me than the list of invoices still to be settled.
If some one pays i click "submit"
Sure, there are other methods but this works very easy.
Robert