Challenge of Documents (as evidence) in Spanish Civil Proceedings

The process of challenging documents is for authentication purposes rather than a probative evaluation of their content. Documents should only be contested when there are doubts about their authenticity, such as possible tampering, authorship, or integrity. This challenge must be specific, outlining the reasons that justify it.

The doctrine of the Supreme Court has stated that 'the authenticity of a document is one thing, and its probative value is quite another' (Supreme Court Judgment, Civil Chamber, March 25, 2004, November 21, 2000, and April 19, 2004).

In the event of a challenge, an 'incident' arises, which is the appropriate procedural moment to propose evidence regarding the authenticity of the documents submitted. If a document is contested for authenticity, the burden of proving and demonstrating its authenticity lies with the presenting party, not the contesting party.

Referring to private documents, which are often contested, Article 326, points 1 and 2 of the Civil Procedure Law (LEC) state that:

1. Private documents will have full probative value in the process, as per Article 319, when their authenticity is not contested by the party they harm.

2. When the authenticity of a private document is challenged, the one who presented it may request a forensic comparison or propose any other means of evidence that is useful and relevant for this purpose.

If authenticity is evident from the comparison or other means of evidence, the procedure will follow what is set out in the third paragraph of Article 320. When authenticity cannot be inferred or no evidence has been proposed, the court will evaluate it according to the rules of sound judgment.

Challenging authenticity is very exceptional. The contesting party may be fined if the court considers that the challenge was made recklessly. Challenging a private document is limited to a discussion of its authenticity, not its content, and the burden of proposing any other means of evidence useful and relevant to clarify the authenticity of the contested document lies with the party whose document is contested.