Hi,
cheques for the bank account have machine readable numbers for a long time. That is largely for the automatic processing of the cheques and speedy (ahem) transaction.
A simple standard code could also benefit any paper and non paper based invoice, bill or other credit notification. I proposed that each paper or electronic bill has to include a area similar to the product bar code stating the date, unique number, summary description, creditor, due date as well as the amount. Electronic bill could include an embedded XML code that presents the same information.
Using a suitable standard programs to decode this information are therefore possible to manage the "paper trail" for households and corporation much easier. Standard decodding libraries make it cost effective to include the extra functionality into all sorts of products.