Consulting, engineering, agencies, IT: when you sell hours, your margin lives between the time worked and the time invoiced. Here is how Odoo links project management, timesheets and invoicing in a single flow.
In short. In Odoo, a client project links three building blocks that live apart everywhere else: tasks (who does what), timesheets (how many hours, logged on the task) and invoicing (time and materials at actual hours, or fixed price by milestones). The quote creates the project, hours are logged against it, and the invoice is generated from the hours or the progress. The result: no more hours lost between the field and the invoice, and profitability visible per project, not just at year-end.
Luxembourg's economy runs largely on services: consulting, IT, engineering firms, agencies, independent professionals. For all these businesses, the product sold is time, and the problem is always the same: worked hours evaporate between the consultant's notebook, the project manager's spreadsheet and the end-of-month invoice. Every hour lost along the way is margin lost. Here is how a complete project flow in Odoo closes that leak.
How does Odoo handle a services project?
Odoo links the quote, the project, the hours and the invoice in one continuous chain. A confirmed quote automatically creates the project and its tasks. Team members log their hours on those tasks, and invoicing draws directly on that data, at actual time or by progress. No re-keying between the sale and the invoice.
In practice, every "service" quote line carries an invoicing policy. That setting, made once per product, then drives the whole behaviour of the flow. The project manager tracks progress in Kanban or Gantt view, sees hours consumed against the budget sold, and knows before the end of the month whether the project is slipping.
Time and materials or fixed price: the two billing models
Service companies live on two business models, and Odoo handles both, including in parallel for the same client.
| Model | What you sell | How Odoo invoices |
|---|---|---|
| Time and materials | Hours or days, at an agreed rate (for example 850 €/day) | The invoice picks up the validated timesheet hours for the period |
| Fixed price | An outcome, at a set price | Invoicing by milestones or progress; hours feed the internal margin tracking |
| Prepaid (hour packs) | A volume of hours bought upfront | Consumed hours draw down the pack, visible to the client |
The point that changes life for managing directors: on fixed price, hours aren't used for invoicing, but they remain the only honest measure of profitability. A fixed-price job sold at 20,000 € that consumes 30 days instead of 22 is a losing project, and without timesheets tied to the project, nobody sees it before the annual accounts. With the Odoo flow, the gap shows up mid-project, while there is still time to react.
Timesheets that actually get filled in
The whole mechanism rests on a human condition: hours have to be logged. The best answer isn't disciplinary, it's ergonomic. In Odoo, time is logged directly on the task, from the browser or the mobile app, with a built-in timer for those who prefer to clock their work. An employee who needs less than two minutes a day to log their time does it; an employee who has to fill in a spreadsheet on Friday evening makes it up.
For the manager, logged hours roll up in real time: by project, by client, by person. The weekly timesheet validation becomes a consistency check, not a reconstruction. And since those same hours feed invoicing, the loop closes with no double entry.
What the full flow changes for a Luxembourg SME
Once the flow is in place, three concrete effects follow. Invoicing speeds up: time-and-materials invoices go out as soon as the period closes, with the service detail attached, which reduces disputes and shortens collection times. Margin becomes visible per project: each project carries its revenue and its costs (hours valued at the employee's real cost, purchases, subcontracting), which lets you decide on numbers rather than gut feeling. And the accounting follows effortlessly: issued invoices post directly into the Luxembourg accounting of the same database, VAT included.
That is the difference between a standalone project tool and an ERP: the standalone tool can track tasks, but it stops where the invoice begins. In Odoo, the same flow runs from the quote to the accounting entry, on the PCN 2020 structure when the database is configured for Luxembourg. To put that choice in context, our guide to Odoo in Luxembourg covers the full picture.
On the implementation side, a projects, timesheets and invoicing scope is a reasonable integration project, not an eighteen-month undertaking: the typical steps are described in our article on how long an Odoo implementation takes, and the budget ranges in the one on the cost of an Odoo implementation.
FAQ
Can Odoo automatically invoice hours worked?
Yes. With a timesheet-based invoicing policy, the invoice picks up the validated hours for the period, valued at the contract rate. You review the invoice before sending it, but you no longer rebuild it.
Can you mix time and materials and fixed price for the same client?
Yes. The invoicing policy is set per quote line: the same client can have a fixed-price project and an hour pack for support. Each flow follows its own invoicing logic.
Do employees have to log their time every day?
It's the practice that works best: a two-minute daily entry on the task, from the browser or mobile, followed by a weekly validation by the manager.
Does Odoo show the profitability of a project in progress?
Yes. Each project consolidates its revenue (invoices, milestones) and its costs (hours at real cost, purchases, subcontracting). The gap between budget sold and consumed shows up during the project, not only at the close.
Why Advena?
- Finance and digital under one roof: the project flow is configured all the way to the accounting entry, not just to the Kanban board.
- Rates and margins in real euros: hour valuation and per-project profitability are set up with a manager's eye, not only a technician's.
- Clear packages, no hourly billing: you know what you pay, right from the start.
- Direct access to the founders: it's the partners who work with you, not a junior.
Going further: Odoo in Luxembourg: is it the right ERP for your SME? · How long does an Odoo implementation take? · How much does an Odoo implementation cost in Luxembourg? · Setting up Luxembourg accounting in Odoo
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