Odoo has two versions - a "Community" version and an "Enterprise" version. The enterprise version is firmly based on the community version and has additional features (such as bank and VoIP integration) to the community version.

Here is a comparison

Odoo Community is free to download and does not require a license. 

Odoo Enterprise, which we recommend to all businesses, requires a license.

Read our Odoo Community vs. Odoo Enterprise blog on which is best for your business here.

Odoo Enterprise Licence

WilldooIT provides comprehensive, on-going system support for base Odoo and any custom written modules.  

Additionally, by purchasing a yearly Odoo Enterprise license, your software is backed by a full publisher's Warranty, including version updates. As in any mission-critical project, it is essential to secure the appropriate services for support, bug fixing and migration services, in order to implement Odoo successfully.  The Enterprise License covers you from the beginning of your project through to future migrations.

The Odoo Enterprise license is available for a fixed annual subscription fee based on the number of users. The Warranty covers maintenance services and migration services and WilldooIT will be able to escalate any bugs to Odoo when necessary.  Odoo will fix these bugs at no extra charge.  

When your company decides to migrate from your current version to a future version of Odoo, we will be able to enable the migration of the certified Odoo modules. As an optional service, you can have all custom development of your Odoo installation certified by Odoo. The benefit of this certification is that the bug fixing and migration services will then apply to your complete installation, and not only the standard Odoo product.