Part-payments of public contracts cut principal first

Partial payments made by a public buyer toward a public contract reduce the principal owed first, not the interest already accrued.Legifrance The Conseil d'État (7th and 2nd chambers sitting together, 19 October 2026, No. 508690) rejected the cassation brought by the commune de Sin-le-NobleLegifrance against a 31 July 2025 execution ruling of the Douai administrative court of appeal, and ordered the commune to pay Eiffage Construction Nord-Pas-de-Calais 3,000 euros under article L. 761-1 of the code de justice administrative.

The contract covered the Paulette Deblock school group. On 21 February 2023 the Douai court raised the balance owed from 48,978.71 euros to 374,993.85 euros inclusive of tax, with contractual interest from 2 September 2015 capitalised yearly from 2 September 2016. Eiffage then asked the same court under article L. 911-4 to secure execution for the interest, claiming 256,737.26 euros up to 8 July 2025 with the later period to be perfected. On 31 July 2025 the court ordered the commune to calculate and pay that interest within two months of notification, at the European Central Bank refinancing rate in force on 1 July 2015 plus eight percentage points.

The commune called the execution request inadmissible as a disguised correction of an error of law and a contradiction between the reasoning and the operative part of the February 2023 ruling; said sums paid should have gone to interest first; and alleged insufficient reasoning on sums paid. The Conseil d'État rejected all three grounds.Legifrance

On the execution judge's office, articles L. 911-1 and L. 911-4 mean that where the decision to be executed has not defined its necessarily implied implementing measures, the judge seised under article L. 911-4 defines them in light of the legal and factual situations on the date of its own decision. Where measures were already prescribed under article L. 911-1, the judge may clarify them if obscure or ambiguousLegifrance and issue new onesLegifrance, but may not call into question measures previously prescribedLegifrance nor disregard the authority of the supporting reasoningLegifrance. Errors can be corrected only through timely appeals against the decision.Legifrance Here Eiffage's request only clarified the applicable interest rate, seeking no correctionLegifrance, so the court stayed within the execution judge's competenceLegifrance.

On imputation, the special public-contract payment provisions applicable to this contract (articles 38 and following of the law of 28 January 2013, since codified in articles L. 2192-12 and following of the code de la commande publique, and articles 1 to 10 of the decree of 29 March 2013, since codified in articles R. 2192-10 and following) set partial payments first against the principal owed by the debtor public entity, not against accrued interestLegifrance. Article 1343-1 of the code civil does not apply to claims held against a contracting authority by the holder of a public contract.Legifrance The sums paid on 15 October 2019 and 4 July 2023 were accordingly set against principal owed on those dates for computing the remaining moratory interestLegifranceLegifrance, with no error of law and sufficient reasoning.

The ruling holds that the commune 'n'est pas fondée à demander l'annulation de l'arrêt qu'elle attaque', rejects the pourvoi in its operative part ('Le pourvoi de la commune de Sin-le-Noble est rejetéLegifrance'), and refuses the commune's own 4,500-euro claim under article L. 761-1 because Eiffage is not the losing party in this instance.

Legal basis: code de justice administrative, articles L. 911-1, L. 911-4 and L. 761-1; law No. 2013-100 of 28 January 2013 and decree No. 2013-269 of 29 March 2013, since codified in the code de la commande publique; code civil, article 1343-1, held inapplicable.