Understanding how billing line item amounts are calculated

When billable time or expenses is submitted for a project, billing line items are generated that you can add to client invoices.

For amounts based on rates, the billable line item is calculated by multiplying the billing rate used by the amount of time worked. However, billing calculation rules are also needed: they specify whether or not billable amounts should be prorated if only partial hours, days, or months were worked, depending on the type of rate in use.

These are Replicon’s default billing calculation rules:

Type of billable amount

Billing calculation rule


The full amount is always billed

Fixed bid project

The full fixed bid amount is billed, either at project completion or after each complete week or month of the project, depending on how billing is set up

Time & Materials project billed at a monthly rate

The full monthly amount is billed if any work is done that month

Time & Materials project billed at an hourly or daily rate

Billing amounts are pro-rated based on the fraction of the hour or day worked

Customizing billing line item amounts

Some customers might want to modify how billing line item amounts are calculated. If you use Replicon Professional Services Automation, you can ask Replicon to update these default rules to match your requirements.

Using custom rules has some advantages. For example, they can:

  • Save you from having to make adjustments to invoices after they’re generated, which saves time and improves accuracy
  • Allow you to apply standard company-wide policies consistently
  • Give you greater billing flexibility

Examples of common customizations include:

  • Bill the full amount for daily projects if any work was completed, not a prorated amount
  • Add discounts to items automatically, such as decreasing all expense billing by a percentage
  • Don’t bill for select ‘free’ hours, such as the first three hours worked in a day
  • Bill select hours at different rates, such as billing the first 5 hours at a base rate, and the remaining daily hours at 1.5x the base rate

Refer to the Administration > Projects > Billing Calculation Rules page to see the rules currently in effect in your system.

If you need your billing calculation rules to be customized or would like more information on this feature, contact your Customer Success Manager or Replicon Support.


Can we configure any of the rules’ parameters ourselves?

No. The interface on the Administration > Projects > Billing Calculation Rules page exists purely so you can see what rules are in effect at any given time. Any customizations will display here, but Replicon makes all customizations based on your requirements.

How do we enable billing calculation rules?

Any rules that display on the Administration > Projects > Billing Calculation Rules are enabled by default.

How do we apply rules to specific clients or projects only?

The rules apply to all clients and projects in your system. However, any custom behaviour specific to particular projects or clients or other variables can be defined within the base rules. Replicon can modify scripts so they run differently, depending on what variables are involved.

What properties can we modify?

Contact your Customer Success Manager or Replicon Support for more information on what sorts of customizations are possible.

Related links

Using Replicon for billing
How billing works
Setting up system billing rates
Creating a new invoice
Sending an invoice to your client