English to Swedish Bus/Financial Law: Contract(s)

I den text om avtal som jag nämnt tidigare finns en lista med betalningsmetoder. I den listan ingår payment in advance or down-payment (prior to delivery), credit card payment (at time of order or on delivery), (cash) payment upon delivery, payment (on delivery), debit note (on delivery), payment by draft (on delivery), payment on straightforward account (after delivery), payment on account with a specified payment date (after delivery).

Vad som menas med payment on straightforward account?

Tack på förhand!