The precautionary measures within the inspection procedure, as provided in article 146 of Law 58/2003, General Tax, of December 17 (hereinafter LGT), are intended to prevent the disappearance, destruction or alteration of the decisive evidence of the existence or compliance of tax obligations or that their existence or display is subsequently denied, said measures having to meet a series of conditions. It is established that:

• They must be proportionate to the purpose they pursue, adopting the measure that causes the least harm to the taxpayer, provided that it is sufficient to secure the evidence in question.

• They cannot be extended indefinitely throughout the entire processing and resolution of the inspection procedure, since they are temporarily limited to the stated purposes.

• Measures that may cause damage to the taxpayer that is difficult or impossible to repair cannot be adopted.

The measures may consist of sealing, depositing or seizing the goods or products subject to tax, as well as books, records, documents, files, premises or electronic data processing equipment that may contain the information to be secured. Article 181.1 of the General Regulations on actions and procedures for tax management and inspection and the development of common rules for procedures for the application of taxes, approved by Royal Decree 1065/2007, of July 27 (hereinafter RGAT ), develops these measures.

The seal is made by means of a sealed ligature or by any other means that allows the closing or tying of books, records, electronic equipment, envelopes, packages, drawers, doors of rooms or premises or other elements of evidence, so that they are not opened without the authorization and control of the Inspection bodies.

The deposit consists of placing the evidence under the custody or safekeeping of the natural or legal person determined by the Administration. The documents or objects deposited may be previously sealed.

The seizure consists of the taking possession of movable evidence by Inspection officials. Seized documents or objects may also be previously sealed.

The precautionary measures adopted within an inspection procedure, in accordance with the provisions of article 146 LGT and 181.4 RGAT, must comply with a series of requirements. This is how they should be:

• Motivated, stating the circumstances and purpose that determine the need to adopt said measure in order to secure the evidence in question.

• Ratified within 15 days of their adoption by the Chief Inspector.

• Documented in the corresponding diligence in which the circumstances and purpose that determine its adoption, the type of precautionary measure and inventory of the goods, documents or other elements affected by it must be stated. Likewise, the taxpayer must be informed of his right to make objections within a period of 5 days.

• Lifted if the circumstances that motivated the adoption of the precautionary measure disappear.

The breach of precautionary measures constitutes an infraction of resistance, obstruction, excuse or refusal to the actions of the Tax Administration, the sanction of which, in accordance with the provisions of article 203.8 of the LGT, consists of a fine of 2% of the turnover of the offender with a minimum of 3,000 euros.

After the adoption of precautionary measures, the chain of custody of the evidence must be ensured, since the guarantee of said chain, although it does not have a specific treatment in the tax regulations as it is the object of analysis, fundamentally, in the criminal field, must also be ensured in the inspection procedure, as occurs with any administrative procedure to which its application is appropriate.

The chain of custody of the evidence obtained after the adoption of precautionary measures certifies the manner in which the tasks of collecting, transferring, handling and storing the objects of evidence were carried out until their analysis, in such a way that the identity between the object initially obtained (sealed, deposited, seized, etc.) and the one finally investigated and reported is guaranteed. To do this, it is necessary to document the various stages through which the objects of evidence have passed, so that there is a record of all the activities carried out by each of the people who come into contact with the evidence, thus ensuring the traceability of the evidence obtained.

The chain of custody provides a guarantee that the evidence being analyzed is the same as that collected during the investigation, so that there are no doubts about the object of said evidence. The integrity of the chain of custody allows us to prove that the evidence obtained in the procedure has been preserved in an integral and appropriate manner, and has not been altered either intentionally or accidentally. In this way, the evidence provided in the proceedings is fully guaranteed and ensures respect for the right to the presumption of innocence and the right to a fair trial with all guarantees.

The violation of the chain of custody affects what is called the plausibility of the expert evidence and, consequently, its legitimacy and validity to serve as evidence in the process. In the event that a breach of such chain of custody is proven, given the instrumental nature of this guarantee, it has the effect of expelling such result from the evidentiary inventory in the event of any doubt as to whether it was the same, although this does not prevent, through other evidence, the certainty of the existence of such evidence being reached.