Invoice project milestones

Milestone-based invoicing is ideal for companies that deliver work in clearly defined stages. Instead of charging the full amount upfront or only at project completion, businesses can invoice customers progressively as each milestone is achieved. This method gives customers a clear view of the work completed and the value received over time.

In Odoo, milestone invoicing is set up at the product level in the Sales app, while milestone tracking and completion are managed in the Projects app. When a milestone is marked as complete, the delivered quantity on the related sales order (SO) line is updated, making it ready for invoicing.

How milestone invoicing works

Milestone invoicing follows a structured workflow involving multiple Odoo apps:

1. Create a product in Sales, configured for milestone invoicing.

2. Create a sales order (SO) with the product.

3. Set up a project in Projects, with associated milestones.

4. When a milestone is completed, mark it as reached. This updates the Delivered quantity on the SO line.

5. Generate an invoice for the completed milestone and send it to the customer.

Important

This guide covers the configuration in the Sales app and the invoicing workflow for milestone-based products.

Creating milestone products

Begin by setting up a service product for milestone invoicing:

1. Navigate to Sales app ‣ Products ‣ Products and click New.

2. Enter the product name and Sales Price.

3. Set Product Type to Service, which reveals the Create on Order field.

4. Choose Project, Project and Task, or Task, depending on how the work should be tracked in the Projects app.

Note

You may also assign a Project Template to the product. Templates can define milestones in advance, but the Quantity (%) field must be manually updated for each new project.

For Invoicing Policy, select Based on Milestones. This ensures delivered quantities update automatically as milestones are completed.

Important

The Based on Milestones option is only available if at least one project with milestones exists.

Defining milestones

Once a milestone product is sold, a Milestones smart button appears on the SO. Click it to view, edit, or create milestones.

The Delivered % reflects the portion of the SO value billed when a milestone is reached.

Example

A pool installation company bills 25% per milestone:

• Site Preparation & Excavation

• Structural Installation

• Plumbing & Equipment Installation

• Finishing & Final Inspection

The team uses a Pool installation project template with these milestones defined. Every new SO with the product triggers a project based on this template.

Invoicing completed milestones

Milestones are tracked in the Projects app (Using milestones).

To mark a milestone as reached from the SO:

1. Click the Milestones smart button.

2. Enable the checkbox in the Reached column for the completed milestone.

3. Return to the SO (via View Sales Order or breadcrumbs). The Delivered column now reflects the milestone’s percentage.

Repeat as additional milestones are reached.

Important

Marking a milestone as reached does not automatically create an invoice—it only updates the SO to indicate the portion ready for billing.

Once the Delivered column is accurate, click Create Invoice to generate the invoice. Continue invoicing as further milestones are completed until all services are fulfilled.