A concession bid of 99.8% — and nobody checked whether it was calculated on the same basis as the competitors
The Council of State suspends the award of the parking concession of the city of Ath because the winner calculated its royalty percentage on costs including VAT, while the competitors did so on costs excluding VAT — two incomparable bases for the same award criterion.
What happened?
On 19 June 2025, the city of Ath launches a simplified European tender for a fifteen-year concession to manage and operate paid on-street parking control: enforcement, fee collection, installation and maintenance of parking meters, and residents' parking cards. Estimated turnover excluding VAT: just over €9 million. The main award criterion (45 of 100 points) is the percentage of operating profit the concessionaire pays back to the city — the highest percentage scores the full 45 points. Three bidders compete: City Parking, Indigo Park Belgium and Interparking. On 5 March 2026, Ath awards the concession to Indigo, based on an offer with an improbably high royalty of 99.8% of operating profit and a guaranteed annual minimum of €350,000. City Parking turns to the Council of State, arguing that this percentage can only work if Indigo calculates its costs including VAT — which would distort the comparison because the other bidders had calculated costs excluding VAT. At the hearing, Indigo confirms that it has indeed included all its expenses VAT-inclusive in the operating account, while City Parking (and apparently Interparking too) had calculated VAT-exclusive. The city defends its 'literal and coherent' reading of its own specifications — but the Council dismantles the text article by article. Article 2.13 speaks of 'cost price' ('prix de revient'), which in principle means VAT-exclusive. Article 2.26 (on taxes) only covers taxes on the parking meters themselves, not general VAT. Article 1.2.4 makes clear that the VAT the concessionaire itself has to pay cannot reduce the base on which the percentage applies, but that is a very different thing from 'deducting costs VAT-inclusive'. The Council concludes that the city has assessed offers built on fundamentally different parameters. That violates the principles of equal treatment and non-discrimination. The suspension is ordered with immediate effect.
Why does this matter?
When a concession's price criterion is a payback percentage rather than a fixed amount, the comparison seems simple: 99.8% beats 90% beats 80%. But the percentage means nothing unless you know what it is calculated against. Here the denominator (operating profit) was slightly different for each bidder, and the contracting authority didn't see it coming. For bid managers active in concessions — parking, waste, sports infrastructure, telecoms — this is a wake-up call: read carefully whether the cost base is defined tightly enough in the specifications, and ask a forum question if it is ambiguous. For contracting authorities the lesson is sharper still: if your award criterion is 'percentage of X', then 'X' must be calculated identically by everyone down to the last cent. Spell that out in your specifications, or don't evaluate before you have clarified it.
The lesson
If you organise a concession with a payback percentage as award criterion, define the calculation base in detail: gross or net turnover, VAT in or out, which cost items deductible, which supporting documents required. If you don't, you will compare apples with pears at evaluation time — which is exactly what the Council reproaches here. As a bid manager facing specifications that mention 'percentage of operating profit' without further definition: ask a forum question on the e-Procurement platform before submitting. An unanswered question may weaken your own position later, but it also gives you a hook to challenge the award if the contracting authority never clarified.
Ask yourself
In your concession specifications or evaluation: can you point to whether each cost item of each bidder was counted with or without VAT, and was that applied consistently?
About this database
The Council of State (Raad van State / Conseil d'État) is Belgium's supreme administrative court. In disputes over public procurement — from contract awards to tenderer exclusions — the Council of State is the final arbiter. The rulings in this database are summarised by TenderWolf in plain language, with practical lessons for tenderers and contracting authorities. View all rulings →