The verdict in three sentences
A group whose Tunisian industrial subsidiary issues 1,500 invoices a month cannot keep uploading e-invoices by hand to the El Fatoora platform run by Tunisie TradeNet (TTN). An Odoo to TTN connector generates the TEIF file, signs it electronically, submits it and pushes each invoice's status back into the ERP. On the Tunisian market such a project costs, as a 2026 order of magnitude, 8,000 to 25,000 TND (about 2,400 to 7,400 EUR or £2,000 to £6,200) and ships in 6 to 10 weeks.
What the mandate changes for the CFO in Paris or London
A Tunisian e-invoice is not a PDF sent by email. It follows TEIF (Tunisian Electronic Invoice Format), a structured XML signed with a certificate from the national certification authority (TunTrust), then lodged on El Fatoora, which assigns a unique reference and stamp. The mandate already covers transactions with the State and public bodies and several sectors, and its scope keeps widening: most manufacturers selling to large accounts are exposed in 2026. For a parent company in Paris or London, the issue is also consolidation: group finance needs the same status data as the local team.
| Step | Manual handling | With an Odoo to TTN connector |
|---|---|---|
| TEIF generation | Export then edit the file, 2 to 3 min per invoice | Automatic when the invoice is posted |
| Electronic signature | USB key on one PC, dedicated operator | Server seal certificate, batch signing |
| Upload to El Fatoora | One by one on the portal | Automatic batch upload via the web service |
| Retrieving the TTN reference | Copied by hand | Written on the Odoo invoice and the customer PDF |
| Rejection follow-up | Found late | Immediate alert with reason |
| Monthly time for 1,500 invoices | 60 to 80 hours | 3 to 5 hours of review |
Most rejections come from master data: wrong customer tax ID, missing VAT rate or stamp duty, line rounding. A connector is only worth it if it comes with a clean-up of customer records and taxes in Odoo.
Project components and cost
The TEIF module in Odoo. It builds on existing invoices (Odoo 16, 17 or 18, Community or Enterprise) and outputs compliant XML, including withholding tax, stamp duty and mandatory notices.
Signing. At volume, a server seal certificate is simplest; it avoids an accountant signing 1,500 invoices one by one with a USB key.
Upload and status return. The connector calls TTN's web service, retrieves the unique reference and status (accepted, rejected) and records them on the invoice. The PDF sent to the customer carries the reference and verification code, and group finance can read the same statuses from Paris or London.
| Item | 2026 order of magnitude | Comment |
|---|---|---|
| El Fatoora membership and per-invoice TTN fees | Per TTN's current scale | Proportional to volume |
| TunTrust signing certificate | A few hundred TND a year | Server seal recommended above 300 invoices a month |
| TEIF module from a local Odoo partner | 8,000 to 15,000 TND (about 2,400 to 4,400 EUR, £2,000 to £3,700) | Generation, signing, simple upload |
| Full project with data clean-up and rejection tracking | 15,000 to 25,000 TND (about 4,400 to 7,400 EUR, £3,700 to £6,200) | Controls, dashboard, training |
| Kolonell simple application | 2,500,000 to 4,000,000 FCFA (3,810 to 6,100 EUR) | Connector and tracking board |
| Kolonell medium application | 4,000,000 to 7,000,000 FCFA (6,100 to 10,670 EUR) | Multi-company, credit notes, group reporting |
| Kolonell maintenance | 35,000 / 75,000 / 120,000 FCFA a month (53 / 114 / 183 EUR) | Tracks format and TTN service changes |
6 to 10 week schedule
Weeks 1 and 2 audit Odoo data (tax IDs, taxes, numbering sequences) and handle El Fatoora membership, often the critical path. Weeks 3 to 6 cover module development and tests on TTN's acceptance environment. Weeks 7 to 10 start with one pilot customer, then full switch-over with double checking during the first month. For a related accounting integration, read connecting accounting and CRM for an agency, and see our custom web applications.
Mini case study
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Claire, group CFO of a Paris-based packaging company, oversees a 220-person metal packaging subsidiary in Tunis that issues 1,500 invoices a month, 40 % of them to large accounts and public bodies. The local team uploads mandated invoices by hand at about 3 minutes each.
Calculation: 1,500 invoices x 3 minutes = 75 hours a month. At a loaded cost of 25 TND an hour, that is 1,875 TND a month, or 22,500 TND (about 6,600 EUR) a year, before payment delays caused by rejections, estimated at 8 days on 5 % of invoices. With a 16,000 TND project from an integrator and 4 hours of remaining monthly review, payback comes in under 10 months, and group finance gains a live view of Tunisian invoicing from Paris.
FAQ
Which Odoo versions are supported?
Versions 15 to 18, Community and Enterprise. For version 13 or 14, upgrading first is often cheaper than adapting the module, and adds 3 to 6 weeks.
Do we need one certificate per signer?
No. A server seal certificate in the company's name is enough for batch signing. Personal USB certificates become unmanageable above 300 invoices a month.
What happens if TTN rejects an invoice?
The invoice moves to rejected in Odoo with the returned reason. The accountant fixes the data, usually a tax ID or rate, and resubmits in one click.
Are credit notes handled?
Yes, they follow the same flow with a reference to the original invoice. For a company issuing 30 to 60 credit notes a month, this must be in scope from day one.
How long must invoices be kept?
E-invoices and their acknowledgements must be kept for at least 10 years. The connector archives the signed XML and the TTN reference in Odoo, with an external backup that group IT can audit.
Let's scope your project. We audit your Odoo data, invoice volume and El Fatoora membership, for a connector in production within 6 to 10 weeks. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
