Project Invoice Withholding / Retainage Management – Track Held-Back Amounts in Odoo
On construction and project contracts, a portion of each invoice is often held back as retainage until the work is substantially complete. Standard Odoo has no way to manage this. This module lets you add a withholding line to a project invoice in one click, tracks every held-back amount, and lets you bill the retained sums back to the customer when the time comes.
What Does This Module Do?
This module brings retainage – also called invoice withholding – to project invoicing in Odoo. Retainage is a portion of the agreed contract price deliberately held back until the work is substantially complete, giving the customer assurance that the contractor will finish the job. You configure a withholding product and percentage once, then on any project invoice you add a withholding line with a single click; the line is created at the configured amount and can still be edited by hand if needed. When the invoice is validated, the withholding is recorded automatically, and every held-back amount is tracked in dedicated list and form views, linked to both the partner and the project. When it’s time to release the retention, you can create a withholding payment invoice for selected lines directly from the partner or the project.
Why Do You Need It?
Retainage is standard practice on construction and long-running project contracts, but Odoo has no built-in way to handle it – so teams end up tracking held-back amounts in spreadsheets, adjusting invoices by hand, and hoping nothing slips through. That’s risky: retained sums that aren’t tracked properly are money you’ve earned but may forget to collect, and manual workarounds make reconciliation and reporting painful. This module puts the whole retainage cycle inside Odoo, where your invoicing already lives. Withholding lines are created consistently from a configured rule, every retained amount is visible and tied to its partner and project, and releasing the retention is a structured action rather than a manual invoice built from memory. The result is fewer errors, cleaner books, and confidence that every held-back amount will eventually be billed and paid.
When Should You Use This Module?
This module is for any business that withholds retainage on project or contract invoicing and runs its accounting in Odoo. It’s ideal for construction firms, contractors and subcontractors, and any project-based business whose contracts hold back a percentage until completion. If your finance team currently tracks retention outside Odoo, adjusts invoice totals manually, or struggles to see how much is being held across projects and customers, this module is built for exactly that. It builds on Odoo Invoicing and Project, so it fits into your existing accounting and project workflow. Note that, like other modules of this type, it runs on Odoo.sh, Cloud, or On Premise and is not available on Odoo Online.
How This Module Works in Practice
First you configure the withholding product and percentage that will be used to build withholding lines. On a project invoice, click once to add a withholding line – it appears at the configured amount and can be edited manually if a particular contract needs a different figure. Validating the invoice creates the withholding record automatically. From there, all withholding lines are visible in their own list and form views, and each line links back to the partner and the project it belongs to. When retention is due for release, you open the withholding invoice wizard from the partner or project, select the lines you want to bill, and create the withholding payment invoice; once payment is created, the lines’ status updates to reflect it. You can also jump straight to all withholding lines for a given project to bill them together.
Product Screenshots
Configuration – set the withholding product and percentage used to build withholding lines
Project Invoice – add a withholding line in one click; it's recorded automatically on validation
Withholding Lines List – every held-back amount tracked in one place
Withholding Line Form – full detail of an individual withholding, linked to partner and project
Release Wizard – from a partner or project, select lines and create a withholding payment invoice
Project Withholdings – jump straight to all withholding lines for a project and bill them together
Key Benefits at a Glance
Retainage in Odoo: manage held-back amounts on project invoices, which standard Odoo can't do.
One-click withholding line: add a withholding line at your configured percentage, editable if needed.
Automatic on validation: the withholding record is created automatically when the invoice is validated.
Full visibility: every withholding line tracked in list and form views, linked to partner and project.
Release with a wizard: bill retained amounts back to the customer from the partner or project, with line status updated on payment.
Ready to get started?
Install the module and go live in minutes — or reach out and we’ll tailor it to your exact contract and retainage workflow.
Have a question or need help? Write to us at [email protected]