Private Documents (not in Spanish) to be used as evidence in Judicial Processes in Spain
In practically every judicial proceeding, private documents are provided, which is why, strictly speaking, it could be stated that it is the most common type of evidence. The LEC (Spanish Civil Procedural Law) considers all those that are not public to be private documents.
As for documents drawn up in a language other than Spanish or, where appropriate, the official language of the Autonomous Community in question, the translation thereof will be attached. Said translation may be made privately and, in such case, if any of the parties contest it within the following five days from the presentation of the document, stating that they do not consider it to be faithful and exact and stating the reasons for the discrepancy, it will be ordered, regarding for the part where there is a discrepancy, the official translation of the document, at the expense of whoever presented it. If the official translation carried out at the request of a party turns out to be substantially identical to the private one, the expenses derived from it will be borne by the person who requested it.
The fact that under the LEC it is not necessary for the translation to be sworn will have to be taken into account for the purposes of the award of judicial costs, since the costs of the official translation may not be included.