C9 now allows you to print statements that contain discounts if bills are paid on time or penalties for non payment on time.  The discount/penalty is applied automatically by c9.

An example bill with this on it:

How to configure

You can configure this option globally in main setup screen under setup.

On time statement bonus gives a percentage bonus on the statement if the bill is paid in a certain period.

The bonus/refund as configured above is currently set to 3%, if the bill is paid within 14 days of the statement. i.e. A January statement will avail the bonus upto and including 14th of January.

The bonus is calculated on the type of invoices raised in the statement period only.  So you can opt to not discount low margin activity like unit sales.

Late payment penalty imposes a % surcharge for component of the bill not paid in time.

Grace period applies to both.  It is used to handle situations such as direct bank deposits where payments are not immediately seen or processed on the same day. It permits a few days of back dating before the effect of the statement condition is realised.

These conditions can be configured on a per customer basis as well. In modify customer:

Finally, conditions on a statement and their status can be reviewed via view customers. There is a button in view customers called 'Statement Conditions'. It shows conditions attached to statements for the highlighted customer and their status