Odoo 13 Enterprise → 16 Community, one giant custom addon — $13,000 fixed

The starting point

The company was running Odoo 13 Enterprise, several years and three versions behind. Over those years, one in-house addon had grown into a monster: custom reports, workflow automations, field changes, business rules — 20–30 distinct pieces of functionality in a single module, touching many parts of the system. Around it sat another 10–15 more ordinary custom modules.

That one giant addon is exactly what stalls upgrades. Nobody wants to touch it, every partner prices in the unknown, and the quote balloons.

What we did

We moved the whole instance to Odoo 16 Community — database and every module. Two things worth noting:

• Enterprise → Community. The upgrade doubled as an edition switch. On top of getting current, the company stopped paying Odoo subscription fees entirely — the free Community edition now covers what they need.
• The monster addon came along whole. Every one of its jobs was carried forward and checked on the new version. No "we'll rebuild this later as a phase two."

The result

$13,000, one fixed price, agreed before work started. The customer got a working copy of their own system on Odoo 16 to test, compared the numbers, clicked through their daily workflows, and paid when satisfied. For comparison, systems in this shape are routinely quoted at $30,000 and up once discovery phases and retainers get bundled in.