Bear in mind certain formalities and time constraints. Also, decide on the tone, style and level of detail of the reply, taking into account the rule of law.

Replying to a (first) RFI

Actually, applicable to any response to an RFI, the following formalities and timings are applicable:

• Replies should be provided in writing (per registered post or (preferably) by mail) to the Belgian tax authorities typically within one month, from the third working day following the date as included in the RFI (sending date by the Belgian tax authorities). If that final day is not a working day (Saturday, Sunday or national public holiday), the next working day is the ultimate deadline date. The answer must be received by the Belgian tax authorities on the ultimate deadline date (therefore: preferably by mail sent with receipt notification). Sending the answer by registered post on the last day is too late. It may also already happen that the tax inspector requests to submit the answers through MyMinfin. The official electronic communication with the tax authorities (e.g. via eBox, MyMinfin) is only foreseen to take place as from 1 January 2025.
  
  
• In practice, an extension of this deadline can be requested if the taxpayer is able to provide legitimate reasons that would justify the need for a longer reply period (e.g., illness, force majeure, extensive research, etc.). In case legitimate reasons can be provided, usually an extension of one additional month is granted. However, note that no formal timing is included in Belgian tax law on this extension and as such, the taxpayer can only count on the willingness of the tax inspector. A refusal to grant an extension of the deadline, however, must be sufficiently justified by the tax authorities.
  
  
• It should be noted that taxpayers who fail to reply within the one-month term or term as agreed upon with the tax inspector, risk the receipt of an ex-officio assessment made by the Belgian tax authorities (with reverse of the tax burden of proof as consequence).
  
  
• Although not applicable to the first RFI received in writing, it should be noted that when an RFI is made orally, it is always appropriate to answer in writing as a proof that the answer was given in time. It is also best practice to ask for a confirmation in writing by the Belgian tax authorities for questions posed orally to determine the starting date of the applicable delays to answer.

In view of extent and nature of reply, we recommend the following:

• Before answering – notwithstanding the information might be available in the group – ask yourself: “Do I generally have access to the information requested at the level of the taxpayer specifically, and am I allowed to share it?” In case, as the specific taxpayer, you do not have access to the information and/or are not allowed to disseminate as such, one should inform the tax inspector of that in a correct and substantiated manner with reference to the legal provisions.
  
  
• In case, upon assessment, the question is not relevant, dare to question relevance, again in a substantiated manner taking into consideration the rules of law. Have the tax inspector explain the rationale of asking the question in such cases.
  
  
• Address the questions raised in a direct and concise manner – i.e. answer the question, nothing more, nothing less.
  
  
• As a taxpayer, keep your tone neutral and polite, yet determined to answer in sync with your obligations with due respect for your rights.
  
  
• In case when the request contains a question to motivate a certain tax filing position, first assess who has the burden of proof to determine the mode and extent of answering.