Why are some accounts missing

Paid through accounts can only be selected if you've enabled payments for them.

What are paid through drop-down menus and where can we find them?

The Paid through drop-down menu is a list of accounts you receive or make payments from.

Paid through drop-downs can be found in invoice payments, bill payments, expenses, payslips, credit note payments, and simplified invoices.

Which accounts will show up in paid through drop-down menus?

All accounts can be listed in paid through drop-downs. While organizing your chart of accounts, simply set your account’s Enable payments column to Yes.