Belgian tax returns from Odoo, and Odoo accounting migrations from any country
The goal?
- No longer having to migrate or retype your Odoo data into other software in order to draw up your tax returns
- Having reliable reports, which you can check before you send them, to make accountants' work easier
- Migrating your accounting data from one Odoo to another (Enterprise --> Enterprise, Enterprise --> Community, Community --> Enterprise…)
Something needs adjusting? You do it directly in Odoo and regenerate the report until it is right.
Your annual accounts for the National Bank
We prepare your annual accounts as an .xbrl file, an xlsx file and a pdf that let you check in detail the content you are about to send.
Check whether your Odoo is compatible
How does it work?
The tool reads your database and generates an XBRL ready to download.
Your data serves to compute the file, then is deleted: nothing is hosted.
Details: the annual accounts page.
The diagnosis is free and commits you to nothing. For what comes after, here is what it costs.
The corporate income tax return for the FPS Finance
Every year you have to file a .biztax file that must satisfy several hundred rules and checks, and attach several PDF files to it.
Our tool prepares the .biztax for assessment year 2026, and gathers the PDFs in one place.
You check the result (xlsx and pdf) before sending it.
Check whether your Odoo is compatible
How does it work?
We copy your accounting data (through an API) into an Odoo database equipped with the module that builds the .biztax file.
Two ways, whichever you prefer: either we host that database for you while you prepare your file, and it is downloadable at any time;
or you install the module in your own Odoo and run it yourself. For that you need an Odoo you host, or odoo.sh: Odoo Online does not install Apps Store modules.
The migration of your accounting
Our tool lets you migrate your accounting from Odoo 17, 18 or 19 to version 19: into a database we host, onto your own server, or onto your standard Odoo Online (a database whose license you pay for at Odoo's own rate).
The takeover of your entries, the whole history, is free.
Check whether your Odoo is compatible
Details: the migration page.
Why we built these tools
This project started at Charbon: every year, its books were properly kept in Odoo, and filing the tax returns still took laborious work.
Two big needs came out of it:
For filing the annual accounts
The standard XBRL export translates booleans into the user's language. You get faux instead of false, and the filing is blocked. It also breaks addresses on an apostrophe, replaces the general meeting date with today's date, and leaves out the statement of fixed assets. You often only notice at the last minute, close to the deadline.
So we built a tool that catches these problems before the filing, with error messages that name the field.
Declaring corporate income tax
Odoo does not produce this return at all. The only XBRL it generates is the one for the annual accounts. On the corporate income tax side, it offers nothing but a checklist.
Accountants come up with all sorts of strategies to move the figures into other software, when the data is already "almost ready" in Odoo.
Our tool prepares the corporate income tax return from your Odoo data.
What you remain responsible for
We would rather say it before you buy than after.
These modules prepare files. They do not check your accounting and do not guarantee that your data is correct. A module reads what is in your Odoo. If the accounting is wrong, the file will be wrong too.
Proofread every file before you submit it. Line by line, with your accountant. A generated file is not a checked file, and the amounts at stake can be very large.
You alone are responsible for what you file. Our liability cannot be engaged.
How we work
We cannot guarantee your figures. We can tell you how the modules are tested.
Compared against accepted filings
We regenerate a financial year already filed and accepted by the Central Balance Sheet Office, then compare fact by fact. As long as one difference remains, it is not done.
Checked with Arelle
Using the authorities' official formulas, which are the same arithmetic checks the Central Balance Sheet Office and the FPS Finance run on your filing.
A negative amount gets named
A balance on the wrong side gets a filing refused. The module names it, account by account, so you reclassify it in your entries. Never disguised inside the XML.
What we do not do
BNB produces a starting point, not a finished filing
The list of directors, the detailed social balance sheet and several notes are entered on filing.cbso.nbb.be. The module tells you which ones.
BNB says which filing models it covers
Its notes are checked on those models. On the others, it leaves those notes blank rather than fill in a wrong value.
Biztax states its tax year
Assessment year 2026. Tax law changes every year; each version says which assessment year it covers.
Belgian accounting only
Abridged scheme, which micro companies may also use. These modules are built for Belgian companies.
Coming from Odoo 17 or 18, fiscal categories are re-entered
After the takeover, you enter your account prefixes again; the delivery screen lists which ones.
If it does not work with your data
No two sets of books look alike. If you bought BNB or Biztax and it does not go through with your data, write to us.
We look at it, without promising to succeed every time. When we do, the fix ships in the next version, for everyone. And in every case, filing stays yours.
Who writes this
Anthracite Brussels is the software brand of Charbon Cinéma, a film post-production lab in Brussels. Our day job is picture and sound: mastering, DCP, restoration.
We have been using Odoo since before Odoo, back when it was still called OpenERP.
We keep our books in it, and every year we file our own annual accounts with the National Bank and our own returns in Biztax. We wrote these modules for ourselves, and they handle our own filings before they are sold.