Luxembourg Administrative Tribunal clarifies limits on appealable tax decisions and “implicit rejections”

The Luxembourg Administrative Tribunal recently clarified the types of administrative decisions in tax matters and the circumstances under which they can be appealed before the tribunal.

Two court decisions (cases 50114 and 52383), dated 17 December 2025, concern the same taxpayer, the same underlying 2021 tax assessments, and the same initial administrative letter. However, they address different procedural attempts to bring the matter before the Administrative Tribunal. Together, these rulings underscore that access to the tribunal is strictly governed by the Abgabenordnung (AO) and Article 8 of the Law of 7 November 1996, and they explain why the general “implicit rejection after three months” mechanism under Article 4 of that law does not apply in direct tax matters.

Unlike a claim, which may be used to challenge tax assessments and notices, the absence of a response to a formal administrative appeal—used to challenge discretionary decisions such as the refusal of a payment extension or the decision to impose an additional tax charge—is currently not appealable before the Administrative Tribunal.

Accordingly, it is crucial to select the correct avenue of appeal. Choosing the wrong procedure may prevent access to the Administrative Tribunal if the director of the Direct Tax Administration remains silent.
 

Factual background

On 15 March 2023, the tax office issued the 2021 income tax assessment. The taxpayers subsequently sent an undated and unsigned letter, received by the tax office on 30 March 2023, in which they asked whether the sale of their property had been treated, for the purposes of the 2021 assessment, as the disposal of a main residence eligible for exemption. In support of their position, they enclosed residence certificates and explained that the property had been used as their main home for many years.

In a letter dated 4 April 2023, the tax office replied that the conditions for the main-residence exemption were not met. The letter contained information on available legal remedies and stated that a formal administrative appeal (“recours hiérarchique formel”) could be filed pursuant to §§ 237, 303 and 304 AO within three months, either with the tax office or the director of the Direct Tax Administration.   

On 15 June 2023, the taxpayer lodged such formal administrative appeal with the Director against the decision of 4 April 2023. The Director did not respond within the following months.

On 13 June 2024, the taxpayer introduced a request for relief from forfeiture (i.e., a request to be relieved from time-bar) on the grounds that the tax office’s decision of 4 April 2023 contained incorrect information about the available legal routes and deadlines for appeal.

On this procedural basis, two separate proceedings were subsequently brought before the Administrative Tribunal:

• Case 50114, based on an alleged “implicit rejection” as of 16 December 2023, resulting from the failure to respond to the formal administrative appeal lodged on 15 June 2023.
• Case 52383, based on an alleged “implicit rejection” as of 14 December 2024, resulting from the failure to respond to the request for relief from forfeiture lodged on 13 June 2024.
   

Case 50114: No appeal against an “implicit rejection” of a formal administrative appeal

As indicated above, in case 50114, following the director’s failure to respond to the formal administrative appeal, the taxpayer filed a judicial appeal (“recours”) against what he characterized as an “implicit rejection” by the director. Only at the stage of the reply brief did the taxpayer argue, in the alternative, that if an appeal against an implicit decision were not found admissible, the appeal should instead be regarded as directed against the original decision of the tax office dated 4 April 2023.

The tribunal recalled that the contested decision must be clearly identified in the introductory petition, as that petition determines the object of the appeal. Established case law does not permit any subsequent extension or modification of that object in later submissions. Since the taxpayer initially challenged only an alleged implicit decision of the Director, the later attempt to redirect the appeal against the tax office’s letter of 4 April 2023 was treated as an inadmissible extension. The tribunal therefore confined its analysis to the sole question of whether an appeal could be brought against an “implicit rejection” in the present tax context.

Turning to the applicable legal framework, the tribunal noted that Article 8 of the Law of 7 November 1996 exhaustively defines the types of tax disputes and the corresponding avenues of appeal. In particular, in the case of formal administrative appeals under § 237 AO against certain tax office decisions that do not constitute tax “assessments” within the meaning of the AO, an appeal before the Tribunal may be brought only against an explicit decision of the director. The tribunal emphasized that, in this specific context, no legal mechanism exists whereby the director’s silence may be construed as a legally appealable “implicit rejection,” in contrast to the general rule laid down in Article 4(1) of the 1996 Law.

The appeal was therefore declared inadmissible, as it was directed against a non‑existent implicit decision and could not, at this procedural stage, be recharacterized as an appeal against the original letter of 4 April 2023.

This outcome highlights a shortcoming in the current procedural framework. It is nevertheless noteworthy that a bill of law dated 28 March 2023—which ultimately did not enter into force— would have allowed taxpayers to bring an appeal before the Administrative Tribunal even in the absence of a response from the Director to a formal administrative appeal.
 

Case 52383: No implicit rejection under Article 4(1) of the 1996 Law for a request for relief from forfeiture

In case 52383, the same taxpayer adopted a different procedural strategy. Following the formal administrative appeal and the Director’s continued silence, the taxpayer filed, on 13 June 2024, a request for relief from forfeiture with the director in relation to the 2021 income tax assessment dated 15 March 2023. The taxpayer argued that the tax office’s decision of 4 April 2023 contained incorrect information regarding the available legal remedies and the applicable deadlines for appeal.

When the Director again failed to respond, the taxpayer brought proceedings before the Administrative Tribunal seeking the annulment of an alleged “implicit decision rejecting” its request for relief from forfeiture. In support of its claim, the taxpayer invoked Article 4(1) of the Law of 7 November 1996, which provides that, in contentious matters that may be brought before the Administrative Tribunal only by way of an appeal against an administrative decision, the absence of a decision within three months allows the parties to treat their request as implicitly rejected and to seize the tribunal.

The taxpayer contended that the dispute did not constitute a “direct tax” dispute in the strict sense but rather concerned the refusal of relief from forfeiture as such. On that basis, the taxpayer argued that Article 4(1) of the 1996 Law should apply, thereby allowing the taxpayer to challenge an implicit rejection of the request.

The tribunal firmly rejected this line of argument. It first recalled that a request for relief from forfeiture within the meaning of §§ 86 and 87 AO—which set out the conditions under which such relief may be sought—cannot be dissociated from its underlying basis, namely an objection against a tax assessment. Consequently, the grounds of objection must be submitted within the same time limit as the request for relief from forfeiture, provided that both are lodged within that period.

The tribunal further recalled that disputes relating to direct taxes falling within its jurisdiction are exhaustively listed in Article 8 of the Law of 7 November 1996. The overall structure of that law, and the specific enumeration in Article 8, demonstrate that the implicit-rejection mechanism provided for in Article 4(1) does not apply to tax matters.

Access to the Administrative Tribunal in tax disputes is governed exclusively by Article 8 of the 1996 Law and by the AO (notably § 228 AO on claims against tax assessments and § 237 AO on formal administrative appeals), and only in the limited case of requests for remission or moderation of taxes. As the taxpayer’s situation concerned neither remission nor moderation, but a request for relief from forfeiture linked to a claim against a tax assessment, the appeal based on the director’s failure to respond was declared inadmissible.
 

Key take-away

Taken together, these two decisions demonstrate that choosing the correct avenue of appeal is critical. Selecting the wrong procedural route may ultimately prevent access to the Administrative Tribunal where the Director of the Direct Tax Administration remains silent.

Under the current legal framework, unlike a claim, the absence of a response to a formal administrative appeal is unfortunately not subject to judicial review before the Administrative Tribunal.

Taxpayers must therefore identify the contested decision with precision from the outset, comply strictly with the applicable procedural routes —whether a claim, a formal administrative appeal, or a request for relief from forfeiture—and observe the corresponding deadlines. They cannot recharacterize their appeal or construct an “implicit” decision in circumstances where tax procedure does not provide for such a mechanism.